# Comparison of programming languages (basic instructions)

This article compares a large number of programming languages by tabulating their data types, their expression, statement, and declaration syntax, and some common operating-system interfaces.

## Conventions of this article

Generally, var, var, or var is how variable names or other non-literal values to be interpreted by the reader are represented. The rest is literal code. Guillemets (« and ») enclose optional sections. Tab ↹ indicates a necessary (whitespace) indentation.
The tables are not sorted lexicographically ascending by programming language name by default, and that some languages have entries in some tables but not others.

## Type identifiers
### Integers

| | 8 bit (byte) | 8 bit (byte) | 16 bit (short integer) | 16 bit (short integer) | 32 bit | 32 bit | 64 bit (long integer) | 64 bit (long integer) | Word size | Word size | Arbitrarily precise (bignum) |
| | Signed | Unsigned | Signed | Unsigned | Signed | Unsigned | Signed | Unsigned | Signed | Unsigned | Arbitrarily precise (bignum) |
| Ada | range -2**7 .. 2**7 - 1 | range 0 .. 2**8 - 1 or mod 2**8 | range -2**15 .. 2**15 - 1 | range 0 .. 2**16 - 1 or mod 2**16 | range -2**31 .. 2**31 - 1 | range 0 .. 2**32 - 1 or mod 2**32 | range -2**63 .. 2**63 - 1 | mod 2**64 | Integer | range 0 .. 2**Integer'Size - 1 or mod Integer'Size | — |
| ALGOL 68 (variable-width) | short short int | — | short int | — | int | — | long int | — | int | — | long long int |
| long long int ||
| C (C99 fixed-width) | int8_t | uint8_t | int16_t | uint16_t | int32_t | uint32_t | int64_t | uint64_t | intptr_t | size_t | — |
| C++ (C++11 fixed-width) | int8_t | uint8_t | int16_t | uint16_t | int32_t | uint32_t | int64_t | uint64_t | intptr_t | size_t | — |
| C (C99 variable-width) | signed char | unsigned char | short | unsigned short | long | unsigned long | long long | unsigned long long | int | unsigned int | — |
| C++ (C++11 variable-width) | signed char | unsigned char | short | unsigned short | long | unsigned long | long long | unsigned long long | int | unsigned int | — |
| Objective-C (Cocoa) | signed char or int8_t | unsigned char or uint8_t | short or int16_t | unsigned short or uint16_t | int or int32_t | unsigned int or uint32_t | long long or int64_t | unsigned long long or uint64_t | NSInteger or long | NSUInteger or unsigned long | — |
| C# | sbyte | byte | short | ushort | int | uint | long | ulong | IntPtr | UIntPtr | System.Numerics.BigInteger (.NET 4.0) |
| Java | byte | — | short | char | int | — | long | — | — | — | java.math.BigInteger |
| Go | int8 | uint8 or byte | int16 | uint16 | int32 | uint32 | int64 | uint64 | int | uint | big.Int |
| Rust | i8 | u8 | i16 | u16 | i32 | u32 | i64 | u64 | isize | usize | — |
| Swift | Int8 | UInt8 | Int16 | UInt16 | Int32 | UInt32 | Int64 | UInt64 | Int | UInt |
| D | byte | ubyte | short | ushort | int | uint | long | ulong | — | — | BigInt |
| Common Lisp | (signed-byte 8) | (unsigned-byte 8) | (signed-byte 16) | (unsigned-byte 16) | (signed-byte 32) | (unsigned-byte 32) | (signed-byte 64) | (unsigned-byte 64) | | | bignum |
| Scheme | | | | | | | | | | | |
| ISLISP | | | | | | | | | | | bignum |
| Pascal (FPC) | shortint | byte | smallint | word | longint | longword | int64 | qword | integer | cardinal | — |
| Visual Basic | — | Byte | Integer | — | Long | — | — | — | — | — | — |
| Visual Basic .NET | SByte | Byte | Short | UShort | Integer | UInteger | Long | ULong | — | — | System.Numerics.BigInteger (.NET 4.0) |
| FreeBasic | Byte or Integer<8> | UByte or UInteger<8> | Short or Integer<16> | UShort or UInteger<16> | Long or Integer<32> | ULong or UInteger<32> | LongInt or Integer<64> | ULongInt or UInteger<64> | Integer | UInteger | — |
| Python 2.x | — | — | — | — | — | — | — | — | int | — | long |
| Python 3.x | — | — | — | — | — | — | — | — | — | — | int |
| S-Lang | — | — | — | — | — | — | — | — | — | — | — |
| Fortran | INTEGER(KIND = n) | — | INTEGER(KIND = n) | — | INTEGER(KIND = n) | — | INTEGER(KIND = n) | — | | | |
| PHP | — | — | — | — | int | — | int | — | — | — | |
| Perl 5 | — | — | — | — | — | — | — | — | — | — | Math::BigInt |
| Raku | int8 | uint8 | int16 | uint16 | int32 | uint32 | int64 | uint64 | Int | — | — |
| Ruby | — | — | — | — | — | — | — | — | Fixnum | — | Bignum |
| Erlang | — | — | — | — | — | — | — | — | integer | — | integer |
| Scala | Byte | — | Short | Char | Int | — | Long | — | — | — | scala.math.BigInt |
| Seed7 | — | — | — | — | — | — | integer | — | — | — | bigInteger |
| Smalltalk | — | — | — | — | — | — | — | — | SmallInteger | — | LargeInteger |
| Windows PowerShell | — | — | — | — | — | — | — | — | — | — | — |
| OCaml | — | — | — | — | int32 | — | int64 | — | int or nativeint | | open Big_int;; or big_int |
| F# | sbyte | byte | int16 | uint16 | int32 or int | uint32 | int64 | uint64 | nativeint | unativeint | bigint |
| Standard ML | — | Word8.word | — | — | Int32.int | Word32.word | Int64.int | Word64.word | int | word | LargeInt.int or IntInf.int |
| Haskell (GHC) | «import Int» or Int8 | «import Word» or Word8 | «import Int» or Int16 | «import Word» or Word16 | «import Int» or Int32 | «import Word» or Word32 | «import Int» or Int64 | «import Word» or Word64 | Int | «import Word» or Word | Integer |
| Eiffel | INTEGER_8 | NATURAL_8 | INTEGER_16 | NATURAL_16 | INTEGER_32 | NATURAL_32 | INTEGER_64 | NATURAL_64 | INTEGER | NATURAL | — |
| COBOL | BINARY-CHAR «SIGNED» | BINARY-CHAR UNSIGNED | BINARY-SHORT «SIGNED» | BINARY-SHORT UNSIGNED | BINARY-LONG «SIGNED» | BINARY-LONG UNSIGNED | BINARY-DOUBLE «SIGNED» | BINARY-DOUBLE UNSIGNED | — | — | — |
| Mathematica | — | — | — | — | — | — | — | — | — | — | Integer |
| Wolfram Language | — | — | — | — | — | — | — | — | — | — | Integer |
* ^a The standard constants int shorts and int lengths can be used to determine how many shorts and longs can be usefully prefixed to short int and long int. The actual sizes of short int, int, and long int are available as the constants short max int, max int, and long max int etc.
* ^b Commonly used for characters.
* ^c The ALGOL 68, C and C++ languages do not specify the exact width of the integer types short, int, long, and (C99, C++11) long long, so they are implementation-dependent. In C and C++ short, long, and long long types are required to be at least 16, 32, and 64 bits wide, respectively, but can be more. The int type is required to be at least as wide as short and at most as wide as long, and is typically the width of the word size on the processor of the machine (i.e. on a 32-bit machine it is often 32 bits wide; on 64-bit machines it is sometimes 64 bits wide). C99 and C++11 also define the [u]intN_t exact-width types in the stdint.h header. See C syntax#Integral types for more information. In addition the types size_t and ptrdiff_t are defined in relation to the address size to hold unsigned and signed integers sufficiently large to handle array indices and the difference between pointers.
* ^d Perl 5 does not have distinct types. Integers, floating point numbers, strings, etc. are all considered "scalars".
* ^e PHP has two arbitrary-precision libraries. The BCMath library just uses strings as datatype. The GMP library uses an internal "resource" type.
* ^f The value of n is provided by the SELECTED_INT_KIND intrinsic function.
* ^g ALGOL 68G's runtime option --precision "number" can set precision for long long ints to the required "number" significant digits. The standard constants long long int width and long long max int can be used to determine actual precision.
* ^h COBOL allows the specification of a required precision and will automatically select an available type capable of representing the specified precision. "PIC S9999", for example, would require a signed variable of four decimal digits precision. If specified as a binary field, this would select a 16-bit signed type on most platforms.
* ^i Smalltalk automatically chooses an appropriate representation for integral numbers. Typically, two representations are present, one for integers fitting the native word size minus any tag bit (SmallInteger) and one supporting arbitrary sized integers (LargeInteger). Arithmetic operations support polymorphic arguments and return the result in the most appropriate compact representation.
* ^j Ada range types are checked for boundary violations at run-time (as well as at compile-time for static expressions). Run-time boundary violations raise a "constraint error" exception. Ranges are not restricted to powers of two. Commonly predefined Integer subtypes are: Positive (range 1 .. Integer'Last) and Natural (range 0 .. Integer'Last). Short_Short_Integer (8 bits), Short_Integer (16 bits) and Long_Integer (64 bits) are also commonly predefined, but not required by the Ada standard. Runtime checks can be disabled if performance is more important than integrity checks.
* ^k Ada modulo types implement modulo arithmetic in all operations, i.e. no range violations are possible. Modulos are not restricted to powers of two.
* ^l Commonly used for characters like Java's char.
* ^m int in PHP has the same width as long type in C has on that system.
* ^n Erlang is dynamically typed. The type identifiers are usually used to specify types of record fields and the argument and return types of functions.
* ^o When it exceeds one word.

### Floating point

| | Single precision | Double precision | Other precision | Processor dependent |
| Ada | Float | Long_Float | — |
| ALGOL 68 | real | long real | short real, long long real, etc. |
| C | float | double | long double |
| C++ (STL) | float | double | long double |
| Objective-C (Cocoa) | float | double | long double | CGFloat |
| C# | float | double | — |
| Java | float | double | — |
| Go | float32 | float64 | — |
| Rust | f32 | f64 | f16, f128 |
| Swift | Float or Float32 | Double or Float64 | Float80 | CGFloat |
| D | float | double | | real |
| Common Lisp | single-float | double-float | float, short-float, long-float |
| Scheme | | | |
| ISLISP | | | |
| Pascal (FPC) | single | double | | real |
| Visual Basic | Single | Double | — |
| Visual Basic .NET | Single | Double | — |
| Xojo | Single | Double | — |
| Python | — | float | |
| JavaScript | — | Number | — |
| S-Lang | | | |
| Fortran | REAL(KIND = n) | REAL(KIND = n) | |
| PHP | | float | |
| Perl | | | |
| Raku | num32 | num64 | | Num |
| Ruby | — | Float | — |
| Scala | Float | Double | — |
| Seed7 | — | float | — |
| Smalltalk | Float | Double | — |
| Windows PowerShell | | | |
| OCaml | — | float | — |
| F# | float32 | float | — |
| Standard ML | — | | — | real |
| Haskell (GHC) | Float | Double | |
| Eiffel | REAL_32 | REAL_64 | |
| COBOL | FLOAT-BINARY-7 | FLOAT-BINARY-34 | FLOAT-SHORT, FLOAT-LONG, FLOAT-EXTENDED |
| Mathematica | — | — | | Real |
* ^a The standard constants real shorts and real lengths can be used to determine how many shorts and longs can be usefully prefixed to short real and long real. The actual sizes of short real, real, and long real are available as the constants short max real, max real and long max real etc. With the constants short small real, small real and long small real available for each type's machine epsilon.
* ^b declarations of single precision often are not honored
* ^c The value of n is provided by the SELECTED_REAL_KIND intrinsic function.
* ^d ALGOL 68G's runtime option --precision "number" can set precision for long long reals to the required "number" significant digits. The standard constants long long real width and long long max real can be used to determine actual precision.
* ^e These IEEE floating-point types will be introduced in the next COBOL standard.
* ^f Same size as double on many implementations.
* ^g Swift supports 80-bit extended precision floating point type, equivalent to long double in C languages.

### Complex numbers

| | Integer | Single precision | Double precision | Half and Quadruple precision etc. |
| Ada | — | Complex | Complex | Complex |
| ALGOL 68 | — | compl | long compl etc. | short compl etc. and long long compl etc. |
| C (C99) | — | float complex | double complex | — |
| C++ (STL) | — | std::complex<float> | std::complex<double> | — |
| C# | — | — | System.Numerics.Complex (.NET 4.0) | — |
| Java | — | — | — | — |
| Go | — | complex64 | complex128 | — |
| D | — | cfloat | cdouble | — |
| Objective-C | — | — | — | — |
| Common Lisp | (complex integer) | (complex single-float) | (complex double-float) | complex |
| Scheme | | | | — |
| Pascal | — | — | | — |
| Visual Basic | — | — | | — |
| Visual Basic .NET | — | — | System.Numerics.Complex (.NET 4.0) | — |
| Perl | | | Math::Complex | |
| Raku | | complex64 | complex128 | Complex |
| Python | | | complex | — |
| JavaScript | — | — | | — |
| S-Lang | — | — | | — |
| Fortran | | COMPLEX(KIND = n) | COMPLEX(KIND = n) | | — |
| Ruby | Complex | — | Complex | — |
| Scala | — | — | — | — |
| Seed7 | — | — | complex | — |
| Smalltalk | Complex | Complex | Complex | — |
| Windows PowerShell | — | — | | — |
| OCaml | — | — | Complex.t | — |
| F# | | | System.Numerics.Complex (.NET 4.0) | — |
| Standard ML | — | — | — | — |
| Haskell (GHC) | — | Complex.Complex Float | Complex.Complex Double | — |
| Eiffel | — | — | — | — |
| COBOL | — | — | — | — |
| Mathematica | Complex | — | — | Complex |
* ^a The value of n is provided by the SELECTED_REAL_KIND intrinsic function.
* ^b Generic type which can be instantiated with any base floating point type.

### Other variable types

| | Text | Text | Boolean | Enumeration | Object/Universal |
| | Character | String | Boolean | Enumeration | Object/Universal |
| Ada | Character | String, Bounded_String, Unbounded_String | Boolean | (item$_1$, item$_2$, ...) | tagged null record |
| ALGOL 68 | char | string, bytes | bool, bits | — - User defined | — |
| C (C99) | char, wchar_t | — | bool | enum «name» { item$_1$, item$_2$, ... }; | void * |
| C++ (STL) | char, wchar_t | «std::»string | bool | enum «name» { item$_1$, item$_2$, ... }; | void * |
| Objective-C | unichar | NSString * | BOOL | enum «name» { item$_1$, item$_2$, ... }; | id |
| C# | char | string | bool | enum name { item$_1$« = value», item$_2$« = value», ... } | object |
| Java | char | String | boolean | enum name { item$_1$, item$_2$, ... } | Object |
| Go | byte, rune | string | bool | const ( item$_1$ = iota item$_2$ ... ) | interface |
| Rust | char | String | bool | enum name { item$_1$« = value», item$_2$« = value», ... } | std::any::Any |
| Swift | Character | String | Bool | enum name { case item$_1$, item$_2$, ... } | Any |
| D | char | string | bool | enum name { item$_1$, item$_2$, ... } | std.variant.Variant |
| Common Lisp | character | string | boolean | (member item$_1$ item$_2$ ...) | t |
| Scheme | | | | | |
| ISLISP | | | | | |
| Pascal (ISO) | char | — | boolean | ( item$_1$, item$_2$, ... ) | — |
| Object Pascal (Delphi) | char | string | boolean | ( item$_1$, item$_2$, ... ) | variant |
| Visual Basic | — | String | Boolean | Enum name item$_1$ «= value» item$_2$ «= value» ... End Enum | [[Variant type|Variant]] |
| Visual Basic .NET | Char | String | Boolean | Enum name item$_1$ «= value» item$_2$ «= value» ... End Enum | Object |
| Xojo | — | String | Boolean | Enum name item$_1$ «= value» item$_2$ «= value» ... End Enum | Object or Variant |
| Python | — | str | bool | from enum import Enum class Name(Enum): item$_1$ = value item$_2$ = value ... | object |
| JavaScript | — | String | Boolean | | Object |
| S-Lang | | | | | |
| Fortran | CHARACTER(LEN = *) | CHARACTER(LEN = :), allocatable | LOGICAL(KIND = n) | | CLASS(*) |
| PHP | — | string | bool | | (type declaration omitted) |
| Perl | — | | | | UNIVERSAL |
| Raku | Char | Str | Bool | enum name<item$_1$ item$_2$ ...> enum name <<:item$_1$(value) :item$_2$(value) ..>> | Mu |
| Ruby | — | String | Object | | Object |
| Scala | Char | String | Boolean | object name extends Enumeration { val item$_1$, item$_2$, ... = Value } | Any |
| Seed7 | char | string | boolean | const type: name is new enum item$_1$, item$_2$, ... end enum; | |
| Windows PowerShell | | | | | |
| OCaml | char | string | bool | — | — |
| F# | char | string | bool | type name = item$_1$ = value |item$_2$ = value | ... | obj |
| Standard ML | char | string | bool | — | — |
| Haskell (GHC) | Char | String | Bool | — | — |
| Eiffel | CHARACTER | STRING | BOOLEAN | — | ANY |
| COBOL | PIC X | PIC X(string length) or PIC X«X...» | PIC 1«(number of digits)» or PIC 1«1...» | — | OBJECT REFERENCE |
| Mathematica | — | String | | | — |
* ^a specifically, strings of arbitrary length and automatically managed.
* ^b This language represents a boolean as an integer where false is represented as a value of zero and true by a non-zero value.
* ^c All values evaluate to either true or false. Everything in TrueClass evaluates to true and everything in FalseClass evaluates to false.
* ^d This language does not have a separate character type. Characters are represented as strings of length 1.
* ^e Enumerations in this language are algebraic types with only nullary constructors
* ^f The value of n is provided by the SELECTED_INT_KIND intrinsic function.

## Derived types
### Array

| | fixed size array | fixed size array | dynamic size array | dynamic size array |
| | one-dimensional array | multidimensional array | one-dimensional array | multidimensional array |
| Ada | array (<first> .. <last>) of <type> or array (<discrete_type>) of <type> | array (<first$_1$> .. <last$_1$>, <first$_2$> .. <last$_2$>, ...) of <type> or array (<discrete_type$_1$>, <discrete_type$_2$>, ...) of <type> | array (<discrete_type> range <>) of <type> | array (<discrete_type$_1$> range <>, <discrete_type$_2$> range <>, ...) of <type> |
| ALGOL 68 | [first:last]«modename» or simply: [size]«modename» | [first$_1$:last$_1$, first$_2$:last$_2$]«modename» or [first$_1$:last$_1$][first$_2$:last$_2$]«modename» etc. | flex[first:last]«modename» or simply: flex[size]«modename» | flex[first$_1$:last$_1$, first$_2$:last$_2$]«modename» or flex[first$_1$:last$_1$]flex[first$_2$:last$_2$]«modename» etc. |
| C (C99) | type name[size] | type name[size$_1$][size$_2$] | type *name or within a block: int n = ...; type name[n] | |
| C++ (STL) | «std::»array<type, size>(C++11) | | «std::»vector<type> | «std::»vector<type> |
| C# | type | type[,,...] | System.Collections.ArrayList or System.Collections.Generic.List<type> | |
| Java | type | type... | ArrayList or ArrayList<type> | |
| D | type[size] | type[size$_1$][size$_2$] | type | |
| Go | [size]type | [size$_1$][size$_2$]...type |type |type |
| Rust | [type; size] | [[type; size$_1$]; size$_2$] | Vec<type> | Vec<Vec<type>> |
| Swift | | | [type] or Array<type> | [[type]] or Array<Array<type>> |
| Objective-C | NSArray | | NSMutableArray | |
| JavaScript | — | — | Array | Array |
| Common Lisp | (simple-array type (dimension)) | (simple-array type (dimension1 dimension2)) | (array type (dimension)) | (array type (dimension1 dimension2)) |
| Scheme | | | | |
| ISLISP | | | | |
| Pascal | array[first..last] of type | array[first$_1$..last$_1$] of array[first$_2$..last$_2$] ... of type or array[first$_1$..last$_1$, first$_2$..last$_2$, ...] of type | — | — |
| Object Pascal (Delphi) | array[first..last] of type | array[first$_1$..last$_1$] of array[first$_2$..last$_2$] ... of type or array[first$_1$..last$_1$, first$_2$..last$_2$, ...] of type | array of type | array of array ... of type |
| Visual Basic | Dim x(last) As type | Dim x(last$_1$, last$_2$,...) As type | | |
| Visual Basic .NET | type | type(,,...) | System.Collections.ArrayList or System.Collections.Generic.List(Of type) | |
| Python | | | list | |
| S-Lang | x = type[size]; | x = type[size$_1$, size$_2$, ...]; | | |
| Fortran | type :: name(size) | type :: name(size$_1$, size$_2$,...) | type, ALLOCATABLE :: name(:) | type, ALLOCATABLE :: name(:,:,...) |
| PHP | | | array | |
| Perl | | | | |
| Raku | | | Array[type] or Array of type | |
| Ruby | | x = Array.new(size$_1$){ Array.new(size$_2$) } | Array | |
| Scala | Array[type] | Array[...[Array[type]]...] | ArrayBuffer[type] | |
| Seed7 | array type or array [idxType] type | array array type or array [idxType] array [idxType] type | array type or array [idxType] type | array array type or array [idxType] array [idxType] type |
| Smalltalk | Array | | OrderedCollection | |
| Windows PowerShell | type | type[,,...] | | |
| OCaml | type array | type array ... array | | |
| F# | type or type array | type [,,...] | System.Collections.ArrayList or System.Collections.Generic.List<type> | |
| Standard ML | type vector or type array | | | |
| Haskell (GHC) | x = Array.array (0, size-1) list_of_association_pairs | x = Array.array ((0, 0,...), (size$_1$-1, size$_2$-1,...)) list_of_association_pairs | | |
| COBOL | level-number type OCCURS size «TIMES». | one-dimensional array definition... | level-number type OCCURS min-size TO max-size «TIMES» DEPENDING «ON» size. | — |
* ^a In most expressions (except the sizeof and & operators), values of array types in C are automatically converted to a pointer of its first argument. See C syntax#Arrays for further details of syntax and pointer operations.
* ^b The C-like type x works in Java, however type x is the preferred form of array declaration.
* ^c Subranges are used to define the bounds of the array.
* ^d JavaScript's array are a special kind of object.
* ^e The DEPENDING ON clause in COBOL does not create a true variable length array and will always allocate the maximum size of the array.

### Other types

| | Simple composite types | Simple composite types | Algebraic data types | Unions |
| | Records | Tuple expression | Algebraic data types | Unions |
| Ada | type name is «abstract» «tagged» «limited» [record field$_1$ : type; field$_2$ : type; ... end record | null record] | — | Any combination of records, unions, and enumerations (as well as references to those, enabling recursive types). | type name (variation : discrete_type) is record case variation is   when choice_list$_1$ =>   fieldname$_1$ : type;   ...   when choice_list$_2$ =>   fieldname$_2$ : type;   ...   ... end case; end record |
| ALGOL 68 | struct (modename «fieldname», ...); | Required types and operators can be user-defined | Required types and operators can be user-defined | union (modename, ...); |
| C (C99) | struct «name» {type name;...}; | — | — | union {type name;...}; |
| Objective-C | struct «name» {type name;...}; | — | — | union {type name;...}; |
| C++ | struct «name» {type name;...}; | «std::»tuple<type$_1$..type$_n$> | — | union {type name;...}; |
| C# | struct name {type name;...} | (val$_1$, val$_2$, ... ) | | — |
| Java | — | | | — |
| JavaScript | | — | | — |
| D | struct name {type name;...} | | std.variant.Algebraic!(type,...) | union {type name;...} |
| Go | struct { «name» type ... } | | | |
| Rust | struct name {name: type, ...} | (val$_1$, val$_2$, ... ) | enum name { Foo(types), ...} | union name {name: type, ...} |
| Swift | struct name { var name «: type» ... } | («name$_1$:» val$_1$, «name$_2$:» val$_2$, «name$_3$:» val$_3$, ... ) | enum name { case Foo«(types)» case Bar «(types)» ... } | |
| Common Lisp | (defstruct name slot-name (slot-name initial-value) (slot-name initial-value :type type) ...) | (cons val$_1$ val$_2$) | | |
| Scheme | — | (cons val$_1$ val$_2$) | | |
| ISLISP | | (cons val$_1$ val$_2$) | | |
| Pascal | record name: type; ... end | — | — | record case type of value: (types); ... end |
| Visual Basic | | | | |
| Visual Basic .NET | Structure name Dim name As type ... End Structure | (val$_1$, val$_2$, ... ) | | |
| Python | — | «(»val$_1$, val$_2$, val$_3$, ... «)» | | — |
| S-Lang | struct {name [=value], ...} | | | |
| Fortran | TYPE name type :: name ... END TYPE | | | |
| PHP | — | | | |
| Perl | — | | | — |
| Raku | — | | | — |
| Ruby | OpenStruct.new({:name => value}) | | | — |
| Scala | case class name(«var» name: type, ...) | (val$_1$, val$_2$, val$_3$, ... ) | abstract class name case class Foo(«parameters») extends name case class Bar(«parameters») extends name ... or abstract class name case object Foo extends name case object Bar extends name ... or a combination of case classes and case objects | |
| Windows PowerShell | | | | |
| OCaml | type name = {«mutable» name : type;...} | «(»val$_1$, val$_2$, val$_3$, ... «)» | type name = Foo «of type» | Bar «of type» | ... | — |
| F# | type name = {«mutable» name : type;...} | «(»val$_1$, val$_2$, val$_3$, ... «)» | type name = Foo «of type» | Bar «of type» | ... | — |
| Standard ML | type name = {name : type,...} | (val$_1$, val$_2$, val$_3$, ... ) | datatype name = Foo «of type» | Bar «of type» | ... | — |
| Haskell | data Name = Constr {name :: type,...} | (val$_1$, val$_2$, val$_3$, ... ) | data Name = Foo «types» | Bar «types» | ... | — |
| COBOL | level-number name type clauses. level-number+n name type clauses. ... | — | — | name REDEFINES variable type. |
* ^a Only classes are supported.
* ^b structs in C++ are actually classes, but have default public visibility and are also POD objects. C++11 extended this further, to make classes act identically to POD objects in many more cases.
* ^c pair only
* ^d Although Perl doesn't have records, because Perl's type system allows different data types to be in an array, "hashes" (associative arrays) that don't have a variable index would effectively be the same as records.
* ^e Enumerations in this language are algebraic types with only nullary constructors

## Variable and constant declarations

| | variable | constant | type synonym |
| Ada | identifier : type« := initial_value» | identifier : constant type := final_value | subtype identifier is type |
| ALGOL 68 | modename name« := initial_value»; | modename name = value; | mode synonym = modename; |
| C (C99) | type name« = initial_value»; | enum{ name = value }; | typedef type synonym; |
| Objective-C | type name« = initial_value»; | enum{ name = value }; | typedef type synonym; |
| C++ | type name« = initial_value»; | const type name = value; | typedef type synonym; |
| C# | type name$_1$« = initial_value», name$_2$« = initial_value», ...; or var name = initial_value; | const type name = value, name = value, ...; or readonly type name = value, name = value, ... ; | using synonym = type; |
| D | type name« = initial_value»; or auto name = value; | const type name = value; or immutable type name = value; | alias type synonym; |
| Java | type name« = initial_value»; | final type name = value; | — |
| JavaScript | var name« = initial_value»; or let name« = initial_value»; (since ECMAScript 2015) | const name = value; (since ECMAScript 2015) | — |
| Go | var name type« = initial_value» or name := initial_value | const name «type» = value | type synonym type |
| Rust | let mut name«: type»« = initial_value»; static mut NAME: type = value; | let name«: type»« = initial_value»; const NAME: type = value; static NAME: type = value; | type synonym = typename; |
| Swift | var name «: type»« = initial_value» | let name «: type» = value | typealias synonym = type |
| Common Lisp | (defparameter name initial-value) or (defvar name initial-value) | (defconstant name value) | (deftype synonym 'type) |
| Scheme | (define name initial_value) | | |
| ISLISP | (defglobal name initial_value) or (defdynamic name initial_value) | (defconstant name value) | — |
| Pascal | name: type« = initial_value» | name = value | synonym = type |
| Visual Basic | Dim name «As type» | See notes to left. Constants use the same syntax, and: use Const instead of Dim have a restriction to only certain primitive types Const name$_1$ «As type» = value, name$_2$ «As type» = value, ... | |
| Visual Basic .NET | The variable declaration syntax of VB.NET is unusually difficult to precisely describe. Given that there exist the identifier suffixes ("modifiers"): type_character, available as an alternative to an As clause for some primitive data types; nullable_specifier; and array_specifier; and that a modified_identifier is of the form identifier«type_character»«nullable_specifier»«array_specifier»; a modified_identifier_list is a comma-separated list of two or more occurrences of modified_identifier; and a declarator_list is a comma-separated list of declarators, which can be of the form identifier As object_creation_expression (object initializer declarator), modified_identifier «As non_array_type«array_rank_specifier»»« = initial_value» (single declarator), or modified_identifier_list «As «non_array_type««array_rank_specifier»» (multiple declarator); valid declaration statements are of the form    Dim declarator_list, where, for the purpose of semantic analysis, to convert the declarator_list to a list of only single declarators: The As clauses of each multiple declarator is distributed over its modified_identifier_list The As New type... of each object initializer declarator is replaced with As type = New type... and for which, for each identifier, a type_character and As clause do not both appear; if an As clause is present, an array_rank_specifier does not appear both as a modification of the identifier and on the type of the As clause; an unmodified_type can be determined, by the rule that, if a type_character or As clause is present, unmodified_type is that specified by such construct, and that otherwise, either Option Infer must be on and the identifier must have an initializer, in which case unmodified_type is that of the initializer, or Option Strict must be off, in which case unmodified_type is Object; its final_type is its unmodified_type prepended before its modifiers; its final_type is a valid type; and if an initial_value is present, either Option Strict is on and initial_value has a widening conversion to final_type, or Option Strict is off and initial_value has a narrowing conversion to final_type. If Option Explicit is off, variables do not require explicit declaration; they are declared implicitly when used: name = initial_value | See notes to left. Constants use the same syntax, and: use Const instead of Dim have a restriction to only certain primitive types Const name$_1$ «As type» = value, name$_2$ «As type» = value, ... | Imports synonym = type |
| Xojo | Dim name «As type»« = initial_value» | See notes to left. Constants use the same syntax, and: use Const instead of Dim have a restriction to only certain primitive types Const name$_1$ «As type» = value, name$_2$ «As type» = value, ... | — |
| Python | name«: type» = initial_value | — | synonym = type |
| CoffeeScript | name = initial_value | — |
| S-Lang | name = initial_value; | | typedef struct {...} typename |
| Fortran | type :: name | type, PARAMETER :: name = value | |
| PHP | $name = initial_value; | define("name", value); const name = value (5.3+) | — |
| Perl | «my» $name« = initial_value»; | use constant name => value; | — |
| Raku | «my «type»» $name« = initial_value»; | «my «type»» constant name = value; | ::synonym ::= type |
| Ruby | name = initial_value | Name = value | synonym = type |
| Scala | var name«: type» = initial_value | val name«: type» = value | type synonym = type |
| Windows PowerShell | «[type]» $name = initial_value | — | — |
| Bash shell | name=initial_value | — | — |
| OCaml | let name« : type ref» = ref value | let name «: type» = value | type synonym = type |
| F# | let mutable name «: type» = value | let name «: type» = value | type synonym = type |
| Standard ML | val name «: type ref» = ref value | val name «: type» = value | type synonym = type |
| Haskell | | «name::type;» name = value | type Synonym = type |
| Forth | VARIABLE name (in some systems use value VARIABLE name instead) | value CONSTANT name | |
| COBOL | level-number name type clauses. | «0»1 name CONSTANT «AS» value. | level-number name type clauses «IS» TYPEDEF. |
| Mathematica | name=initial_value | — | — |
* ^a Pascal has declaration blocks. See functions.
* ^b Types are just regular objects, so you can just assign them.
* ^c In Perl, the "my" keyword scopes the variable into the block.
* ^d Technically, this does not declare name to be a mutable variable—in ML, all names can only be bound once; rather, it declares name to point to a "reference" data structure, which is a simple mutable cell. The data structure can then be read and written to using the ! and := operators, respectively.
* ^e If no initial value is given, an invalid value is automatically assigned (which will trigger a run-time exception if it used before a valid value has been assigned). While this behaviour can be suppressed it is recommended in the interest of predictability. If no invalid value can be found for a type (for example in case of an unconstraint integer type), a valid, yet predictable value is chosen instead.
* ^f In Rust, if no initial value is given to a let or let mut variable and it is never assigned to later, there is an "unused variable" warning. If no value is provided for a const or static or static mut variable, there is an error. There is a "non-upper-case globals" error for non-uppercase const variables. After it is defined, a static mut variable can only be assigned to in an unsafe block or function.

## Control flow
### Conditional statements

| | if | else if | select case | conditional expression |
| Ada | if condition then statements «else statements» end if | if condition$_1$ then statements elsif condition$_2$ then statements ... «else statements» end if | case expression is when value_list$_1$ => statements when value_list$_2$ => statements ... «when others => statements» end case | (if condition$_1$ then expression$_1$ «elsif condition$_2$ then expression$_2$» ... else expression$_n$ ) or (case expression is when value_list$_1$ => expression$_1$ when value_list$_2$ => expression$_2$ ... «when others => expression$_n$» ) |
| Seed7 | if condition then statements «else statements» end if | if condition$_1$ then statements elsif condition$_2$ then statements ... «else statements» end if | case expression of when set1 : statements ... «otherwise: statements» end case | |
| Modula-2 | if condition then statements «else statements» end | if condition$_1$ then statements elsif condition$_2$ then statements ... «else statements» end | case expression of caseLabelList : statements | ... «else statements» end | |
| ALGOL 68 | if condition then statements «else statements» fi | if condition then statements elif condition then statements fi | case switch in statements, statements«,... out statements» esac | ( condition | valueIfTrue | valueIfFalse ) |
| ALGOL 68 (brief form) | ( condition | statements «| statements» ) | ( condition | statements |: condition | statements ) | ( variable | statements,... «| statements» ) | |
| APL | :If condition instructions «:Else instructions» :EndIf | :If condition instructions :ElseIf condition instructions ... «:Else instructions» :EndIf | :Select expression :Case case1   instructions ... «:Else   instructions» :EndSelect | {condition:valueIfTrue ⋄ valueIfFalse} |
| C (C99) | if (condition) instructions «else instructions» instructions can be a single statement or a block in the form of: { statements } | if (condition) instructions else if (condition) instructions ... «else instructions» or if (condition) instructions else { if (condition) instructions } | switch (variable) { case case1: instructions «; break;» ... «default: instructions» } | condition ? valueIfTrue : valueIfFalse |
| Objective-C | if (condition) instructions «else instructions» instructions can be a single statement or a block in the form of: { statements } | if (condition) instructions else if (condition) instructions ... «else instructions» or if (condition) instructions else { if (condition) instructions } | switch (variable) { case case1: instructions «; break;» ... «default: instructions» } | condition ? valueIfTrue : valueIfFalse |
| C++ (STL) | if (condition) instructions «else instructions» instructions can be a single statement or a block in the form of: { statements } | if (condition) instructions else if (condition) instructions ... «else instructions» or if (condition) instructions else { if (condition) instructions } | switch (variable) { case case1: instructions «; break;» ... «default: instructions» } | condition ? valueIfTrue : valueIfFalse |
| D | if (condition) instructions «else instructions» instructions can be a single statement or a block in the form of: { statements } | if (condition) instructions else if (condition) instructions ... «else instructions» or if (condition) instructions else { if (condition) instructions } | switch (variable) { case case1: instructions «; break;» ... «default: instructions» } | condition ? valueIfTrue : valueIfFalse |
| Java | if (condition) instructions «else instructions» instructions can be a single statement or a block in the form of: { statements } | if (condition) instructions else if (condition) instructions ... «else instructions» or if (condition) instructions else { if (condition) instructions } | switch (variable) { case case1: instructions «; break;» ... «default: instructions» } | condition ? valueIfTrue : valueIfFalse |
| JavaScript | if (condition) instructions «else instructions» instructions can be a single statement or a block in the form of: { statements } | if (condition) instructions else if (condition) instructions ... «else instructions» or if (condition) instructions else { if (condition) instructions } | switch (variable) { case case1: instructions «; break;» ... «default: instructions» } | condition ? valueIfTrue : valueIfFalse |
| PHP | if (condition) instructions «else instructions» instructions can be a single statement or a block in the form of: { statements } | if (condition) instructions else if (condition) instructions ... «else instructions» or if (condition) instructions else { if (condition) instructions } | switch (variable) { case case1: instructions «; break;» ... «default: instructions» } | condition ? valueIfTrue : valueIfFalse |
| C# | if (condition) instructions «else instructions» instructions can be a single statement or a block in the form of: { statements } | if (condition) instructions else if (condition) instructions ... «else instructions» | switch (variable) { case case$_1$:   instructions   «break_or_jump_statement» ... «default:   instructions   break_or_jump_statement» } All non-empty cases must end with a break or goto case statement (that is, they are not allowed to fall-through to the next case). The default case is not required to come last. | condition ? valueIfTrue : valueIfFalse |
| Windows PowerShell | if (condition) instruction «else instructions» | if (condition) { instructions } elseif (condition) { instructions } ... «else { instructions }» | switch (variable) { case1{instructions «break;» } ... «default { instructions }»} | |
| Go | if condition {instructions} «else {instructions}» | if condition {instructions} else if condition {instructions} ... «else {instructions}» or switch { case condition: instructions ... «default: instructions» } | switch variable { case case$_1$: instructions ... «default: instructions» } | |
| Swift | if condition {instructions} «else {instructions}» | if condition {instructions} else if condition {instructions} ... «else {instructions}» | switch variable { case case$_1$: instructions ... «default: instructions» } | |
| Perl | if (condition) {instructions} «else {instructions}» or unless (notcondition) {instructions} «else {instructions}» | if (condition) {instructions} elsif (condition) {instructions} ... «else {instructions}» or unless (notcondition) {instructions} elsif (condition) {instructions} ... «else {instructions}» | use feature "switch"; ... given (variable) { when (case$_1$) { instructions } ... «default { instructions }» } | condition ? valueIfTrue : valueIfFalse |
| Raku | if condition {instructions} «else {instructions}» or unless notcondition {instructions} | if condition {instructions} elsif condition {instructions} ... «else {instructions} | given variable { when case$_1$ { instructions } ... «default { instructions }» } | condition ?? valueIfTrue !! valueIfFalse |
| Ruby | if condition instructions «else instructions» | if condition instructions elsif condition instructions ... «else instructions» end | case variable when case$_1$   instructions ... «else   instructions» end | condition ? valueIfTrue : valueIfFalse |
| Scala | if (condition) {instructions} «else {instructions}» | if (condition) {instructions} else if (condition) {instructions} ... «else {instructions}» | expression match { case pattern1 => expression case pattern2 => expression ... «case _ => expression» } | if (condition) valueIfTrue else valueIfFalse |
| Smalltalk | condition ifTrue: trueBlock «ifFalse: falseBlock» end | | | condition ifTrue: trueBlock ifFalse: falseBlock |
| Common Lisp | (when condition instructions) or (unless condition instructions) or (if condition (progn instructions) «(progn instructions)») | (cond (condition1 instructions) (condition2 instructions) ... «(t instructions)») | (case expression (case1 instructions) (case2 instructions) ... «(otherwise instructions)») | (if test then else) or (cond (test1 value1) (test2 value2) ...)) |
| Scheme | (when condition instructions) or (if condition (begin instructions) «(begin instructions)») | (cond (condition1 instructions) (condition2 instructions) ... «(else instructions)») | (case (variable) ((case1) instructions) ((case2) instructions) ... «(else instructions)») | (if condition valueIfTrue valueIfFalse) |
| ISLISP | (if condition (progn instructions) «(progn instructions)») | (cond (condition1 instructions) (condition2 instructions) ... «(t instructions)») | (case expression (case1 instructions) (case2 instructions) ... «(t instructions)») | (if condition valueIfTrue valueIfFalse) |
| Pascal | if condition then begin instructions end «else begin instructions end»' | if condition then begin instructions end else if condition then begin instructions end ... «else begin instructions end» | case variable of case1: instructions ... «else: instructions» end |
| Visual Basic | If condition Then instructions «Else instructions» End If Single-line, when instructions are instruction$_1$ : instruction$_2$ : ...: If condition Then instructions «Else instructions» | If condition Then instructions ElseIf condition Then instructions ... «Else instructions» End If Single-line: See note about C-like languages; the Else clause of a single-line If statement can contain another single-line If statement. | Select« Case» variable Case case_pattern$_1$   instructions ... «Case Else   instructions» End Select | IIf(condition, valueIfTrue, valueIfFalse) |
| Visual Basic .NET | If condition Then instructions «Else instructions» End If Single-line, when instructions are instruction$_1$ : instruction$_2$ : ...: If condition Then instructions «Else instructions» | If condition Then instructions ElseIf condition Then instructions ... «Else instructions» End If Single-line: See note about C-like languages; the Else clause of a single-line If statement can contain another single-line If statement. | Select« Case» variable Case case_pattern$_1$   instructions ... «Case Else   instructions» End Select | If(condition, valueIfTrue, valueIfFalse) |
| Xojo | If condition Then instructions «Else instructions» End If Single-line, when instructions are instruction$_1$ : instruction$_2$ : ...: If condition Then instructions «Else instructions» | If condition Then instructions ElseIf condition Then instructions ... «Else instructions» End If Single-line: See note about C-like languages; the Else clause of a single-line If statement can contain another single-line If statement. | Select« Case» variable Case case_pattern$_1$   instructions ... «Case Else   instructions» End Select | If(condition, valueIfTrue, valueIfFalse) |
| Python | if condition : Tab ↹instructions «else: Tab ↹instructions» | if condition : Tab ↹instructions elif condition : Tab ↹instructions ... «else: Tab ↹instructions» | Python 3.10+: match variable: Tab ↹case case1: Tab ↹Tab ↹instructions Tab ↹case case2: Tab ↹Tab ↹instructions | Python 2.5+: valueIfTrue if condition else valueIfFalse |
| S-Lang | if (condition) { instructions } «else { instructions }» | if (condition) { instructions } else if (condition) { instructions } ... «else { instructions }» | switch (variable) { case case1: instructions } { case case2: instructions } ... | |
| Fortran | IF (condition) THEN instructions ELSE instructions ENDIF | IF (condition) THEN instructions ELSEIF (condition) THEN instructions ... ELSE instructions ENDIF | SELECT CASE(variable) CASE (case1)   instructions ... CASE DEFAULT   instructions END SELECT | |
| Forth | condition IF instructions « ELSE instructions» THEN | condition IF instructions ELSE condition IF instructions THEN THEN | value CASE case OF instructions ENDOF case OF instructions ENDOF   default instructions ENDCASE | condition IF valueIfTrue ELSE valueIfFalse THEN |
| OCaml | if condition then begin instructions end «else begin instructions end» | if condition then begin instructions end else if condition then begin instructions end ... «else begin instructions end» | match value with pattern1 -> expression | pattern2 -> expression ... «| _ -> expression» | if condition then valueIfTrue else valueIfFalse |
| F# | Lightweight syntax mode: Either on a single line or with indentation as shown below: if condition then Tab ↹instructions «else Tab ↹instructions» Verbose syntax mode: Same as Standard ML. | Lightweight syntax mode: Either on a single line or with indentation as shown below: if condition then Tab ↹instructions elif condition then Tab ↹instructions ... «else Tab ↹instructions» Verbose syntax mode: Same as Standard ML. | match value with pattern1 -> expression | pattern2 -> expression ... «| _ -> expression» | if condition then valueIfTrue else valueIfFalse |
| Standard ML | if condition then «(»instructions «)» else «(» instructions «)» | if condition then «(»instructions «)» else if condition then «(» instructions «)» ... else «(» instructions «)» | case value of pattern1 => expression | pattern2 => expression ... «| _ => expression» | if condition then valueIfTrue else valueIfFalse |
| Haskell (GHC) | if condition then expression else expression or when condition (do instructions) or unless notcondition (do instructions) | result | condition = expression | condition = expression | otherwise = expression | case value of { pattern1 -> expression; pattern2 -> expression; ... «_ -> expression» } | if condition then valueIfTrue else valueIfFalse |
| Bash shell | if condition-command; then expression «else expression» fi | if condition-command; then expression elif condition-command; then expression «else expression» fi | case "$variable" in "$condition1" )   command... "$condition2" )   command... esac | |
| CoffeeScript | if condition then expression «else expression» or if condition expression «else expression» or expression if condition or unless condition expression «else expression» or expression unless condition | if condition then expression else if condition then expression «else expression» or if condition expression else if condition expression «else expression» or unless condition expression else unless condition expression «else expression» | switch expression when condition then expression else expression or switch expression when condition   expression «else   expression» | All conditions are expressions. |
| COBOL | IF condition «THEN» expression «ELSE expression». | | EVALUATE expression «ALSO expression...» WHEN case-or-condition «ALSO case-or-condition...»   expression ... «WHEN OTHER   expression» END-EVALUATE | |
| Rust | if condition { expression }« else { expression }» | if condition { expression } else if condition { expression }« else { expression }» | match variable { pattern1 => expression, pattern2 => expression, pattern3 => expression, «_ => expression» } | All conditions are expressions |
| | if | else if | select case | conditional expression |
* ^a A single instruction can be written on the same line following the colon. Multiple instructions are grouped together in a block which starts on a newline (The indentation is required). The conditional expression syntax does not follow this rule.
* ^b This is pattern matching and is similar to select case but not the same. It is usually used to deconstruct algebraic data types.
* ^c In languages of the Pascal family, the semicolon is not part of the statement. It is a separator between statements, not a terminator.
* ^d END-IF may be used instead of the period at the end.
* ^e In Rust, the comma (,) at the end of a match arm can be omitted after the last match arm, or after any match arm in which the expression is a block (ends in possibly empty matching brackets).

### Loop statements

| | while loop | do while loop | (count-controlled) for loop | foreach |
| Ada | while condition loop statements end loop | loop statements exit when not condition end loop | for index in «reverse» [first .. last | discrete_type] loop statements end loop | for item of «reverse» iterator loop statements end loop or (for [all | some] [in | of] [first .. last | discrete_type | iterator] => predicate) |
| ALGOL 68 | «for index» «from first» «by increment» «to last» «while condition» do statements od | «for index» «from first» «by increment» «to last» «while condition» do statements od | «for index» «from first» «by increment» «to last» «while condition» do statements od | for key «to upb list» do «typename val=list[key];» statements od |
| ALGOL 68 | «while condition» do statements od | «while statements; condition» do statements od | «for index» «from first» «by increment» «to last» do statements od | for key «to upb list» do «typename val=list[key];» statements od |
| APL | :While condition statements :EndWhile | :Repeat statements :Until condition | :For var«s» :In list statements :EndFor | :For var«s» :InEach list statements :EndFor |
| C (C99) | instructions can be a single statement or a block in the form of: { statements } while (condition) instructions | do instructions while (condition); | for («type» i = first; i <= last; i++) instructions | — |
| Objective-C | instructions can be a single statement or a block in the form of: { statements } while (condition) instructions | do instructions while (condition); | for («type» i = first; i <= last; i++) instructions | for (type item in set) instructions |
| C++ (STL) | instructions can be a single statement or a block in the form of: { statements } while (condition) instructions | do instructions while (condition); | for («type» i = first; i <= last; i++) instructions | «std::»for_each(start, end, function) Since C++11: for (type item : set) instructions |
| C# | instructions can be a single statement or a block in the form of: { statements } while (condition) instructions | do instructions while (condition); | for («type» i = first; i <= last; i++) instructions | foreach (type item in set) instructions |
| Java | instructions can be a single statement or a block in the form of: { statements } while (condition) instructions | do instructions while (condition); | for («type» i = first; i <= last; i++) instructions | for (type item : set) instructions |
| JavaScript | instructions can be a single statement or a block in the form of: { statements } while (condition) instructions | do instructions while (condition); | for (var i = first; i <= last; i++) instructions | Since EcmaScript 2015: for (var item of set) instructions |
| PHP | instructions can be a single statement or a block in the form of: { statements } while (condition) instructions | do instructions while (condition); | foreach (range(first, last) as $i) instructions or for ($i = first; $i <= last; $i++) instructions | foreach (set as item) instructions or foreach (set as key => item) instructions |
| Windows PowerShell | instructions can be a single statement or a block in the form of: { statements } while (condition) instructions | do instructions while (condition); | for ($i = first; $i -le last; $i++) instructions | foreach (item in set) instructions |
| D | instructions can be a single statement or a block in the form of: { statements } while (condition) instructions | do instructions while (condition); | foreach (i; first ... last) instructions | foreach («type» item; set) instructions |
| Go | for condition { instructions } | | for i := first; i <= last; i++ { instructions } | for key, item := range set { instructions } |
| Swift | while condition { instructions } | 2.x: repeat { instructions } while condition 1.x: do { instructions } while condition | for i = first ... last { instructions } or for i = first ..< last+1 { instructions } or for var i = first; i <= last; i++ { instructions } | for item in set { instructions } |
| Perl | while (condition) { instructions } or until (notcondition) { instructions } | do { instructions } while (condition) or do { instructions } until (notcondition) | for«each» «$i» (first .. last) { instructions } or for ($i = first; $i <= last; $i++) { instructions } | for«each» «$item» (set) { instructions } |
| Raku | while condition { instructions } or until notcondition { instructions } | repeat { instructions } while condition or repeat { instructions } until notcondition | for first..last -> $i { instructions } or loop ($i = first; $i <=last; $i++) { instructions } | for set« -> $item» { instructions } |
| Ruby | while condition instructions end or until notcondition instructions end | begin instructions end while condition or begin instructions end until notcondition | for i in first..last instructions end or for i in first...last+1 instructions end or first.upto(last) { |i| instructions } | for item in set instructions end or set.each { |item| instructions } |
| Bash shell | while condition ;do instructions done or until notcondition ;do instructions done | — | for ((i = first; i <= last; ++i)) ; do instructions done | for item in set ;do instructions done |
| Scala | while (condition) { instructions } | do { instructions } while (condition) | for (i <- first to last «by 1») { instructions } or first to last «by 1» foreach (i => { instructions }) | for (item <- set) { instructions } or set foreach (item => { instructions }) |
| Smalltalk | conditionBlock whileTrue: loopBlock | loopBlock doWhile: conditionBlock | first to: last do: loopBlock | collection do: loopBlock |
| Common Lisp | (loop while condition do instructions) or (do (notcondition) instructions) | (loop do instructions while condition) | (loop for i from first to last «by 1» do instructions) or (dotimes (i N) instructions) or (do ((i first (1+ i))) ((>=i last)) instructions) | (loop for item in list do instructions) or (loop for item across vector do instructions) or (dolist (item list) instructions) or (mapc function list) or (map type function sequence) |
| Scheme | (do (notcondition) instructions) or (let loop (if condition (begin instructions (loop)))) | (let loop (instructions (if condition (loop)))) | (do ((i first (+ i 1))) ((>= i last)) instructions) or (let loop ((i first)) (if (< i last) (begin instructions (loop (+ i 1))))) | (for-each (lambda (item) instructions) list) |
| ISLISP | (while condition instructions) | (tagbody loop instructions (if condition (go loop)) | (for ((i first (+ i 1))) ((>= i last)) instructions) | (mapc (lambda (item) instructions) list) |
| Pascal | while condition do begin instructions end | repeat instructions until notcondition; | for i := first «step 1» to last do begin instructions end; | for item in set do instructions |
| Visual Basic | Do While condition instructions Loop or Do Until notcondition instructions Loop or While condition instructions Wend (Visual Basic .NET uses End While instead) | Do instructions Loop While condition or Do instructions Loop Until notcondition | i must be declared beforehand. For i = first To last «Step 1» instructions Next i | For Each item In set instructions Next item |
| Visual Basic .NET | Do While condition instructions Loop or Do Until notcondition instructions Loop or While condition instructions Wend (Visual Basic .NET uses End While instead) | Do instructions Loop While condition or Do instructions Loop Until notcondition | For i« As type» = first To last« Step 1» instructions Next« i» | For Each item« As type» In set instructions Next« item» |
| Xojo | While condition instructions Wend | Do Until notcondition instructions Loop or Do instructions Loop Until notcondition | For i« As type» = first To last« Step 1» instructions Next« i» | For Each item« As type» In set instructions Next« item» |
| Python | while condition : Tab ↹instructions «else: Tab ↹instructions» | — | Python 3.x: for i in range(first, last+1): Tab ↹instructions «else: Tab ↹instructions» Python 2.x: for i in xrange(first, last+1): Tab ↹instructions «else: Tab ↹instructions» | for item in set: Tab ↹instructions «else: Tab ↹instructions» |
| S-Lang | while (condition) { instructions } «then optional-block» | do { instructions } while (condition) «then optional-block» | for (i = first; i <= last; i++) { instructions } «then optional-block» | foreach item(set) «using (what)» { instructions } «then optional-block» |
| Fortran | DO WHILE (condition) instructions ENDDO | DO instructions IF (condition) EXIT ENDDO | DO I = first,last instructions ENDDO | — |
| Forth | BEGIN «instructions» condition WHILE instructions REPEAT | BEGIN instructions condition UNTIL | limit start DO instructions LOOP | — |
| OCaml | while condition do instructions done | — | for i = first to last do instructions done | Array.iter (fun item -> instructions) array or List.iter (fun item -> instructions) list |
| F# | while condition do Tab ↹instructions | — | for i = first to last do Tab ↹instructions | foritem in set do Tab ↹instructions or Seq.iter (fun item -> instructions) set |
| Standard ML | while condition do ( instructions ) | — | — | Array.app (fn item => instructions) array or app (fn item => instructions) list |
| Haskell (GHC) | — | — | Control.Monad.forM_ [first..last] (\i -> do instructions) | Control.Monad.forM_list (\item -> do instructions) |
| Eiffel | from setup until condition loop instructions end | from setup until condition loop instructions end | from setup until condition loop instructions end | from setup until condition loop instructions end |
| CoffeeScript | while condition expression or expression while condition or while condition then expression or until condition expression or expression until condition or until expression then condition | — | for i in [first..last] expression or for i in [first..last] then expression or expression for i in [first..last] | for item in set expression or for item in set then expression or expression for item in set |
| COBOL | PERFORM procedure-1 «THROUGH procedure-2» ««WITH» TEST BEFORE» UNTIL condition or PERFORM ««WITH» TEST BEFORE» UNTIL condition expression END-PERFORM | PERFORM procedure-1 «THROUGH procedure-2» «WITH» TEST AFTER UNTIL condition or PERFORM «WITH» TEST AFTER UNTIL condition expression END-PERFORM | PERFORM procedure-1 «THROUGH procedure-2» VARYING i FROM first BY increment UNTIL i > last or PERFORM VARYING i FROM first BY increment UNTIL i > last expression END-PERFORM | — |
| Rust | while condition { expression } | loop { expression   if condition {   break; } } | for i in first..last+1 { expression } or for i in first..=last { expression } | for item in set { expression } or set.into_iter.for_each(|item| expression); |
* ^a "step n" is used to change the loop interval. If "step" is omitted, then the loop interval is 1.
* ^b This implements the universal quantifier ("for all" or "$\forall$") as well as the existential quantifier ("there exists" or "$\exists$").
* ^c THRU may be used instead of THROUGH.
* ^d «IS» GREATER «THAN» may be used instead of >.
* ^e Type of set expression must implement trait std::iter::IntoIterator.

### Exceptions

| | throw | handler | assertion |
| Ada | raise exception_name «with string_expression» | begin statements exception when exception_list$_1$ => statements; when exception_list$_2$ => statements; ... «when others => statements;» end | pragma Assert («Check =>» boolean_expression ««Message =>» string_expression») [function | procedure | entry] with Pre => boolean_expression Post => boolean_expression any_type with Type_Invariant => boolean_expression |
| APL | «string_expression» ⎕SIGNAL number_expression | :Trap number«s»_expression statements «:Case number«s»_expression statements» ... «:Else number«s»_expression statements» :EndTrap | «string_expression» ⎕SIGNAL 98/⍨~condition |
| C (C99) | longjmp(state, exception); | switch (setjmp(state)) { case 0: instructions break; case exception: instructions ... } | assert(condition); |
| C++ | throw exception; | try { instructions } catch «(exception)» { instructions } ... | assert(condition); |
| C# | throw exception; | try { instructions } catch «(exception« name»)» { instructions } ... «finally { instructions }» | System.Diagnostics.Debug.Assert(condition); or System.Diagnostics.Trace.Assert(condition); |
| Java | throw exception; | try { instructions } catch (exception) { instructions } ... «finally { instructions }» | assert condition «: description»; |
| JavaScript | throw exception; | try { instructions } catch (exception) { instructions} «finally { instructions }» | ? |
| D | throw exception; | try { instructions } catch (exception) { instructions } ... «finally { instructions }» | assert(condition); |
| PHP | throw exception; | try { instructions } catch (exception) { instructions } ... «finally { instructions }» | assert(condition); |
| S-Lang | throw exception; | try { instructions } catch «exception» { instructions } ... «finally { instructions }» | ? |
| Windows PowerShell | throw exception; | trap «[exception]» { instructions } ... instructions or try { instructions } catch «[exception]» { instructions } ... «finally { instructions }» | [Debug]::Assert(condition) |
| Objective-C | @throw exception; | @try { instructions } @catch (exception) { instructions } ... «@finally { instructions }» | NSAssert(condition, description); |
| Swift | throw exception (2.x) | do { try expression ... instructions } catch exception { instructions } ... (2.x) | assert(condition«, description») |
| Perl | die exception; | eval { instructions }; if ($@) { instructions } | ? |
| Raku | die exception; | try { instructions CATCH { when exception { instructions } ...}} | ? |
| Ruby | raise exception | begin instructions rescue exception instructions ... «else instructions» «ensure instructions» end | |
| Smalltalk | exception raise | instructionBlock on: exception do: handlerBlock | assert: conditionBlock |
| Common Lisp | (error "exception") or (error type arguments) or (error (make-condition type arguments)) | (handler-case (progn instructions) (exception instructions) ...) or (handler-bind (condition   (lambda   instructions   «invoke-restart restart args»)) ...) | (assert condition) or (assert condition «(place) «error»») or (check-type var type) |
| Scheme (R$^6$RS) | (raise exception) | (guard (con (condition instructions) ...) instructions) | ? |
| ISLISP | (error "error-string" objects) or (signal-condition condition continuable) | (with-handler handler form* ) | ? |
| Pascal | raise Exception.Create | try Except on E: exception do begin instructions end; end; | ? |
| Visual Basic | Err.Raise ERRORNUMBER | With New Try: On Error Resume Next OneInstruction .Catch: On Error GoTo 0: Select Case .Number Case SOME_ERRORNUMBER   instructions End Select: End With'*** Try class *** Private mstrDescription As String Private mlngNumber As Long Public Sub Catch mstrDescription = Err.Description mlngNumber = Err.Number End Sub Public Property Get Number As Long Number = mlngNumber End Property Public Property Get Description As String Description = mstrDescription End Property | Debug.Assert condition |
| Visual Basic .NET | Throw exception or Error errorcode | Try instructions Catch« name As exception»« When condition» instructions ... «Finally instructions» End Try | System.Diagnostics.Debug.Assert(condition) or System.Diagnostics.Trace.Assert(condition) |
| Xojo | Raise exception | Try instructions Catch «exception» instructions ... «Finally instructions» End Try | — |
| Python | raise exception | try: Tab ↹instructions except «exception»: Tab ↹instructions ... «else: Tab ↹instructions» «finally: Tab ↹instructions» | assert condition |
| Fortran | — | — | — |
| Forth | code THROW | xt CATCH ( code or 0 ) | — |
| OCaml | raise exception | try expression with pattern -> expression ... | assert condition |
| F# | raise exception | try expression with pattern -> expression ... or try expression finally expression | assert condition |
| Standard ML | raise exception «arg» | expression handle pattern => expression ... | |
| Haskell (GHC) | throw exception or throwError expression | catch tryExpression catchExpression or catchError tryExpression catchExpression | assert condition expression |
| COBOL | RAISE «EXCEPTION» exception | USE «AFTER» EXCEPTION OBJECT class-name. or USE «AFTER» EO class-name. or USE «AFTER» EXCEPTION CONDITION exception-name «FILE file-name». or USE «AFTER» EC exception-name «FILE file-name». | — |
| Rust | No | No | assert!(condition) |
* ^a Common Lisp allows with-simple-restart, restart-case and restart-bind to define restarts for use with invoke-restart. Unhandled conditions may cause the implementation to show a restarts menu to the user before unwinding the stack.
* ^b Uncaught exceptions are propagated to the innermost dynamically enclosing execution. Exceptions are not propagated across tasks (unless these tasks are currently synchronised in a rendezvous).

### Other control flow statements

| | exit block (break) | continue | label | branch (goto) | return value from generator |
| Ada | exit «loop_name» «when condition» | — | label: | goto label | — |
| ALGOL 68 | value exit; ... | do statements; skip exit; label: statements od | label: ... | go to label; ... goto label; ... label; ... | yield(value) (Callback) |
| APL | :Leave | :Continue | label: | →label or :GoTo label | — |
| C (C99) | break; | continue; | label: | goto label; | — |
| Objective-C | break; | continue; | label: | goto label; | — |
| C++ (STL) | break; | continue; | label: | goto label; | — |
| D | break; | continue; | label: | goto label; | — |
| C# | break; | continue; | label: | goto label; | yield return value; |
| Java | break «label»; | continue «label»; | label: | — | |
| JavaScript | break «label»; | continue «label»; | label: | — | yield value«;» |
| PHP | break «levels»; | continue «levels»; | label: | goto label; | yield «key =>» value; |
| Perl | last «label»; | next «label»; | label: | goto label; | |
| Raku | last «label»; | next «label»; | label: | goto label; | |
| Go | break «label» | continue «label» | label: | goto label | |
| Swift | break «label» | continue «label» | label: | — | |
| Bash shell | break «levels» | continue «levels» | — | — | — |
| Common Lisp | (return) or (return-from block) or (loop-finish) | | (tagbody tag ... tag ...) | (go tag) | |
| Scheme | | | | | |
| ISLISP | (return-from block) | | (tagbody tag ... tag ...) | (go tag) | |
| Pascal (ISO) | — | — | label: | goto label; | — |
| Pascal (FPC) | break; | continue; | label: | goto label; | — |
| Visual Basic | Exit blockAlternatively, for methods, Return | — | label: | GoTo label | — |
| Xojo | Exit blockAlternatively, for methods, Return | Continue block | label: | GoTo label | — |
| Visual Basic .NET | Exit blockAlternatively, for methods, Return | Continue block | label: | GoTo label | Yield value |
| Python | break | continue | — | — | yield value |
| RPG IV | LEAVE; | ITER; | | | |
| S-Lang | break; | continue; | | | |
| Fortran | EXIT | CYCLE | label | GOTO label | — |
| Ruby | break | next | | | |
| Windows PowerShell | break «label» | continue | | | |
| OCaml | — | — | — | — | |
| F# | — | — | — | — | |
| Standard ML | — | — | — | — | |
| Haskell (GHC) | — | — | — | — | |
| COBOL | EXIT PERFORM or EXIT PARAGRAPH or EXIT SECTION or EXIT. | EXIT PERFORM CYCLE | label «SECTION». | GO TO label | — |
* ^a Pascal has declaration blocks. See functions.
* ^b label must be a number between 1 and 99999.

## Functions

See reflective programming for calling and declaring functions by strings.
| | calling a function | basic/void function | value-returning function | required main function |
| Ada | foo «(parameters)» | procedure foo «(parameters)» is begin statements end foo | function foo «(parameters)» return type is begin statements end foo | — |
| ALGOL 68 | foo «(parameters)»; | proc foo = «(parameters)» void: ( instructions ); | proc foo = «(parameters)» rettype: ( instructions ...; retvalue ); | — |
| APL | «parameters» foo parameters | foo←{ statements } | foo←{ statements } | — |
| C (C99) | foo(«parameters») | void foo(«parameters») { instructions } | type foo(«parameters») { instructions ... return value; } | «global declarations» int main(«int argc, char *argv») { instructions } |
| Objective-C | foo(«parameters») | void foo(«parameters») { instructions } | type foo(«parameters») { instructions ... return value; } | «global declarations» int main(«int argc, char *argv») { instructions } |
| C++ (STL) | foo(«parameters») | void foo(«parameters») { instructions } | type foo(«parameters») { instructions ... return value; } | «global declarations» int main(«int argc, char *argv») { instructions } |
| Java | foo(«parameters») | void foo(«parameters») { instructions } | type foo(«parameters») { instructions ... return value; } | public static void main(String args) { instructions } or public static void main(String... args) { instructions } |
| D | foo(«parameters») | void foo(«parameters») { instructions } | type foo(«parameters») { instructions ... return value; } | int main(«char args») { instructions} or int main(«string args») { instructions} or void main(«char args») { instructions} or void main(«string args») { instructions} |
| C# | foo(«parameters») | Same as above; alternatively, if only one statement: void foo(«parameters») => statement; | Same as above; alternatively, if simple enough to be an expression: void foo(«parameters») => expression; | static void Main(«string args») method_body May instead return int. (starting with C# 7.1:) May return Task or Task<int>, and if so, may be async. |
| JavaScript | foo(«parameters») | function foo(«parameters») { instructions } or var foo = function («parameters») { instructions } or var foo = new Function ("«parameter»", ..., "«last parameter»" "instructions"); | function foo(«parameters») { instructions ... return value; } | — |
| Go | foo(«parameters») | func foo(«parameters») { instructions } | func foo(«parameters») type { instructions ... return value } | func main { instructions } |
| Swift | foo(«parameters») | func foo(«parameters») { instructions } | func foo(«parameters») -> type { instructions ... return value } | — |
| Common Lisp | (foo «parameters») | (defun foo («parameters») instructions) or (setf (symbol-function 'symbol) function) | (defun foo («parameters») ... value) | — |
| Scheme | (foo «parameters») | (define (foo parameters) instructions) or (define foo (lambda (parameters) instructions)) | (define (foo parameters) instructions... return_value) or (define foo (lambda (parameters) instructions... return_value)) | — |
| ISLISP | (foo «parameters») | (defun foo («parameters») instructions) | (defun foo («parameters») ... value) | — |
| Pascal | foo«(parameters)» | procedure foo«(parameters)»; «forward;» «label label declarations» «const constant declarations» «type type declarations» «var variable declarations» «local function declarations» begin instructions end; | function foo«(parameters)»: type; «forward;» «label label declarations» «const constant declarations» «type type declarations» «var variable declarations» «local function declarations» begin instructions; foo := value end; | program name; «label label declarations» «const constant declarations» «type type declarations» «var variable declarations» «function declarations» begin instructions end. |
| Visual Basic | Foo(«parameters») | Sub Foo«(parameters)» instructions End Sub | Function Foo«(parameters)»« As type» instructions Foo = value End Function | Sub Main instructions End Sub |
| Visual Basic .NET | Foo(«parameters») | Sub Foo«(parameters)» instructions End Sub | Same as above; alternatively: Function Foo«(parameters)»« As type» instructions Return value End Function The As clause is not required if Option Strict is off. A type character may be used instead of the As clause. If control exits the function without a return value having been explicitly specified, the function returns the default value for the return type. | Sub Main(««ByVal »args As String») instructions End Subor Function Main(««ByVal »args As String») As Integer instructions End Function |
| Xojo | Foo(«parameters») | Sub Foo«(parameters)» instructions End Sub | Same as above; alternatively: Function Foo«(parameters)»« As type» instructions Return value End Function The As clause is not required if Option Strict is off. A type character may be used instead of the As clause. If control exits the function without a return value having been explicitly specified, the function returns the default value for the return type. | Sub Main(««ByVal »args As String») instructions End Subor Function Main(««ByVal »args As String») As Integer instructions End Function |
| Python | foo(«parameters») | def foo(«parameters»): Tab ↹instructions | def foo(«parameters»): Tab ↹instructions Tab ↹return value | — |
| S-Lang | foo(«parameters» «;qualifiers») | define foo («parameters») { instructions } | define foo («parameters») { instructions ... return value; } | public define slsh_main { instructions } |
| Fortran | foo («arguments») CALL sub_foo («arguments») | SUBROUTINE sub_foo («arguments») instructions END SUBROUTINE | type FUNCTION foo («arguments») instructions ... foo = value END FUNCTION | PROGRAM main instructions END PROGRAM |
| Forth | «parameters» FOO | : FOO « stack effect comment: ( before -- ) » instructions ; | : FOO « stack effect comment: ( before -- after ) » instructions ; | — |
| PHP | foo(«parameters») | function foo(«parameters») { instructions } | function foo(«parameters») { instructions ... return value; } | — |
| Perl | foo(«parameters») or &foo«(parameters)» | sub foo { «my (parameters) = @_;» instructions } | sub foo { «my (parameters) = @_;» instructions... «return» value; } | — |
| Raku | foo(«parameters») or &foo«(parameters)» | «multi »sub foo(parameters) { instructions } | «our «type» »«multi »sub foo(parameters) { instructions ... «return» value; } | — |
| Ruby | foo«(parameters)» | def foo«(parameters)» instructions end | def foo«(parameters)» instructions «return» value end | — |
| Rust | foo(«parameters») | fn foo(«parameters») { instructions } | fn foo(«parameters») -> type { instructions } | fn main { instructions } |
| Scala | foo«(parameters)» | def foo«(parameters)»«: Unit =» { instructions } | def foo«(parameters)»«: type» = { instructions ... «return» value } | def main(args: Array[String]) { instructions } |
| Windows PowerShell | foo «parameters» | function foo { instructions }; or function foo { «param(parameters)» instructions } | function foo «(parameters)» { instructions ... return value }; or function foo { «param(parameters)» instructions ... return value } | — |
| Bash shell | foo «parameters» | function foo { instructions } or foo { instructions } | function foo { instructions return «exit_code» } or foo { instructions return «exit_code» } | — |
| OCaml | foo parameters | let «rec» foo parameters = instructions | let «rec» foo parameters = instructions... return_value | — |
| F# | foo parameters | let «rec» foo parameters = instructions | let «rec» foo parameters = instructions... return_value | [<EntryPoint>] let main args = instructions |
| Standard ML | foo parameters | fun foo parameters = ( instructions ) | fun foo parameters = ( instructions... return_value ) | |
| Haskell | foo parameters | foo parameters = do Tab ↹instructions | foo parameters = return_value or foo parameters = do Tab ↹instructions Tab ↹return value | «main :: IO» main = do instructions |
| Eiffel | foo («parameters») | foo («parameters») require   preconditions do   instructions ensure   postconditions end | foo («parameters»): type require   preconditions do   instructions   Result := value ensure   postconditions end | |
| CoffeeScript | foo | foo = -> | foo = -> value | — |
| CoffeeScript | foo parameters | foo = -> | foo = ( parameters ) -> value | — |
| COBOL | CALL "foo" «USING parameters» «exception-handling» «END-CALL» | «IDENTIFICATION DIVISION.» PROGRAM-ID. foo. «other divisions...» PROCEDURE DIVISION «USING parameters». instructions. | «IDENTIFICATION DIVISION.» PROGRAM-ID/FUNCTION-ID. foo. «other divisions...» DATA DIVISION. «other sections...» LINKAGE SECTION. «parameter definitions...» variable-to-return definition «other sections...» PROCEDURE DIVISION «USING parameters» RETURNING variable-to-return. instructions. | — |
| COBOL | «FUNCTION» foo«(«parameters»)» | — | «IDENTIFICATION DIVISION.» PROGRAM-ID/FUNCTION-ID. foo. «other divisions...» DATA DIVISION. «other sections...» LINKAGE SECTION. «parameter definitions...» variable-to-return definition «other sections...» PROCEDURE DIVISION «USING parameters» RETURNING variable-to-return. instructions. | — |
* ^a Pascal requires "forward;" for forward declarations.
* ^b Eiffel allows the specification of an application's root class and feature.
* ^c In Fortran, function/subroutine parameters are called arguments (since PARAMETER is a language keyword); the CALL keyword is required for subroutines.
* ^d Instead of using "foo", a string variable may be used instead containing the same value.

## Type conversions

Where string is a signed decimal number:
| | string to integer | string to long integer | string to floating point | integer to string | floating point to string |
| Ada | Integer'Value (string_expression) | Long_Integer'Value (string_expression) | Float'Value (string_expression) | Integer'Image (integer_expression) | Float'Image (float_expression) |
| ALGOL 68 with general, and then specific formats | With prior declarations and association of: string buf := "12345678.9012e34 "; file proxy; associate(proxy, buf); | With prior declarations and association of: string buf := "12345678.9012e34 "; file proxy; associate(proxy, buf); | With prior declarations and association of: string buf := "12345678.9012e34 "; file proxy; associate(proxy, buf); | With prior declarations and association of: string buf := "12345678.9012e34 "; file proxy; associate(proxy, buf); | With prior declarations and association of: string buf := "12345678.9012e34 "; file proxy; associate(proxy, buf); |
| ALGOL 68 with general, and then specific formats | get(proxy, ivar); | get(proxy, livar); | get(proxy, rvar); | put(proxy, ival); | put(proxy, rval); |
| ALGOL 68 with general, and then specific formats | getf(proxy, ($g$, ivar)); or getf(proxy, ($dddd$, ivar)); | getf(proxy, ($g$, livar)); or getf(proxy, ($8d$, livar)); | getf(proxy, ($g$, rvar)); or getf(proxy, ($8d.4dE2d$, rvar)); | putf(proxy, ($g$, ival)); or putf(proxy, ($4d$, ival)); | putf(proxy, ($g(width, places, exp)$, rval)); or putf(proxy, ($8d.4dE2d$, rval)); |
| APL | ⍎string_expression | ⍎string_expression | ⍎string_expression | ⍕integer_expression | ⍕float_expression |
| C (C99) | integer = atoi(string); | long = atol(string); | float = atof(string); | sprintf(string, "%i", integer); | sprintf(string, "%f", float); |
| Objective-C | integer = [string intValue]; | long = [string longLongValue]; | float = [string doubleValue]; | string = [NSString stringWithFormat:@"%i", integer]; | string = [NSString stringWithFormat:@"%f", float]; |
| C++ (STL) | «std::»istringstream(string) >> number; | «std::»istringstream(string) >> number; | «std::»istringstream(string) >> number; | «std::»ostringstream o; o << number; string = o.str; | «std::»ostringstream o; o << number; string = o.str; |
| C++11 | integer = «std::»stoi(string); | long = «std::»stol(string); | float = «std::»stof(string); double = «std::»stod(string); | string = «std::»to_string(number); | string = «std::»to_string(number); |
| C# | integer = int.Parse(string); | long = long.Parse(string); | float = float.Parse(string);double = double.Parse(string); | string = number.ToString; | string = number.ToString; |
| D | integer = std.conv.to!int(string) | long = std.conv.to!long(string) | float = std.conv.to!float(string) double = std.conv.to!double(string) | string = std.conv.to!string(number) | string = std.conv.to!string(number) |
| Java | integer = Integer.parseInt(string); | long = Long.parseLong(string); | float = Float.parseFloat(string); double = Double.parseDouble(string); | string = Integer.toString(integer); string = String.valueOf(integer); | string = Float.toString(float); string = Double.toString(double); |
| JavaScript | integer = parseInt(string); | integer = parseInt(string); | float = parseFloat(string); float = new Number (string); float = Number (string); float = +string; | string = number.toString; string = String (number); string = number+""; string = `${number}` | string = number.toString; string = String (number); string = number+""; string = `${number}` |
| Go | integer, error = strconv.Atoi(string) integer, error = strconv.ParseInt(string, 10, 0) | long, error = strconv.ParseInt(string, 10, 64) | float, error = strconv.ParseFloat(string, 64) | string = strconv.Itoa(integer) string = strconv.FormatInt(integer, 10) string = fmt.Sprint(integer) | string = strconv.FormatFloat(float) string = fmt.Sprint(float) |
| Rust | string.parse::<i32> i32::from_str(string) | string.parse::<i64> i64::from_str(string) | string.parse::<f64> f64::from_str(string) | integer.to_string | float.to_string |
| Common Lisp | (setf integer (parse-integer string)) | (setf integer (parse-integer string)) | (setf float (read-from-string string)) | (setf string (princ-to-string number)) | (setf string (princ-to-string number)) |
| Scheme | (define number (string->number string)) | (define number (string->number string)) | (define number (string->number string)) | (define string (number->string number)) | (define string (number->string number)) |
| ISLISP | (setf integer (convert string <integer>)) | (setf integer (convert string <integer>)) | (setf float (convert string <float>)) | (setf string (convert number <string>)) | (setf string (convert number <string>)) |
| Pascal | integer := StrToInt(string); | | float := StrToFloat(string); | string := IntToStr(integer); | string := FloatToStr(float); |
| Visual Basic | integer = CInt(string) | long = CLng(string) | float = CSng(string) double = CDbl(string) | string = CStr(number) | |
| Visual Basic .NET (can use both VB syntax above and .NET methods shown right) | integer = Integer.Parse(string) | long = Long.Parse(string) | float = Single.Parse(string) double = Double.Parse(string) | string = number.ToString | string = number.ToString |
| Xojo | integer = Val(string) | long = Val(string) | double = Val(string) double = CDbl(string) | string = CStr(number) or string = Str(number) | string = CStr(number) or string = Str(number) |
| Python | integer = int(string) | long = long(string) | float = float(string) | string = str(number) | string = str(number) |
| S-Lang | integer = atoi(string); | long = atol(string); | float = atof(string); | string = string(number); | string = string(number); |
| Fortran | READ(string,format) number | READ(string,format) number | READ(string,format) number | WRITE(string,format) number | WRITE(string,format) number |
| PHP | integer = intval(string); or integer = (int)string; | integer = intval(string); or integer = (int)string; | float = floatval(string); float = (float)string; | string = "$number"; or string = strval(number); or string = (string)number; | string = "$number"; or string = strval(number); or string = (string)number; |
| Perl | number = 0 + string; | number = 0 + string; | number = 0 + string; | string = "number"; | string = "number"; |
| Raku | number = +string; | number = +string; | number = +string; | string = ~number; | string = ~number; |
| Ruby | integer = string.to_i or integer = Integer(string) | integer = string.to_i or integer = Integer(string) | float = string.to_f float = Float(string) | string = number.to_s | string = number.to_s |
| Scala | integer = string.toInt | long = string.toLong | float = string.toFloatdouble = string.toDouble | string = number.toString | string = number.toString |
| Smalltalk | integer := Integer readFrom: string | integer := Integer readFrom: string | float := Float readFrom: string | string := number asString | string := number asString |
| Windows PowerShell | integer = [int]string | long = [long]string | float = [float]string | string = [string]number; or string = "number"; or string = (number).ToString | string = [string]number; or string = "number"; or string = (number).ToString |
| OCaml | let integer = int_of_string string | | let float = float_of_string string | let string = string_of_int integer | let string = string_of_float float |
| F# | let integer = int string | let integer = int64 string | let float = float string | let string = string number | let string = string number |
| Standard ML | val integer = Int.fromString string | | val float = Real.fromString string | val string = Int.toString integer | val string = Real.toString float |
| Haskell (GHC) | number = read string | number = read string | number = read string | string = show number | string = show number |
| COBOL | MOVE «FUNCTION» NUMVAL(string) TO number | MOVE «FUNCTION» NUMVAL(string) TO number | MOVE «FUNCTION» NUMVAL(string) TO number | MOVE number TO numeric-edited | MOVE number TO numeric-edited |
* ^a JavaScript only uses floating point numbers so there are some technicalities.
* ^b Perl doesn't have separate types. Strings and numbers are interchangeable.
* ^c NUMVAL-C or NUMVAL-F may be used instead of NUMVAL.
* ^ str::parse is available to convert any type that has an implementation of the std::str::FromStr trait. Both str::parse and FromStr::from_str return a Result that contains the specified type if there is no error. The turbofish (::<_>) on str::parse can be omitted if the type can be inferred from context.

## Standard stream I/O

| | read from | write to | write to |
| | stdin | stdout | stderr |
| Ada | Get (x) | Put (x) | Put (Standard_Error, x) |
| ALGOL 68 | readf(($format$, x)); or getf(stand in, ($format$, x)); | printf(($format$, x)); or putf(stand out, ($format$, x)); | putf(stand error, ($format$, x)); |
| APL | x←⎕ | ⎕←x | ⍞←x |
| C (C99) | scanf(format, &x); or fscanf(stdin, format, &x); | printf(format, x); or fprintf(stdout, format, x); | fprintf(stderr, format, x); |
| Objective-C | data = [[NSFileHandle fileHandleWithStandardInput] readDataToEndOfFile]; | [[NSFileHandle fileHandleWithStandardOutput] writeData:data]; | [[NSFileHandle fileHandleWithStandardError] writeData:data]; |
| C++ | «std::»cin >> x; or «std::»getline(«std::»cin, str); | «std::»cout << x; | «std::»cerr << x; or «std::»clog << x; |
| C# | x = Console.Read; or x = Console.ReadLine; | Console.Write(«format, »x); or Console.WriteLine(«format, »x); | Console.Error.Write(«format, »x); or Console.Error.WriteLine(«format, »x); |
| D | x = std.stdio.readln | std.stdio.write(x) or std.stdio.writeln(x) or std.stdio.writef(format, x) or std.stdio.writefln(format, x) | stderr.write(x) or stderr.writeln(x) or std.stdio.writef(stderr, format, x) or std.stdio.writefln(stderr, format, x) |
| Java | x = System.in.read; or x = new Scanner(System.in).nextInt; or x = new Scanner(System.in).nextLine; | System.out.print(x); or System.out.printf(format, x); or System.out.println(x); | System.err.print(x); or System.err.printf(format, x); or System.err.println(x); |
| Go | fmt.Scan(&x) or fmt.Scanf(format, &x) or x = bufio.NewReader(os.Stdin).ReadString('\n') | fmt.Println(x) or fmt.Printf(format, x) | fmt.Fprintln(os.Stderr, x) or fmt.Fprintf(os.Stderr, format, x) |
| Swift | x = readLine (2.x) | print(x) (2.x) println(x) (1.x) | |
| JavaScript Web Browser implementation | | document.write(x) | |
| JavaScript Active Server Pages | | Response.Write(x) | |
| JavaScript Windows Script Host | x = WScript.StdIn.Read(chars) or x = WScript.StdIn.ReadLine | WScript.Echo(x) or WScript.StdOut.Write(x) or WScript.StdOut.WriteLine(x) | WScript.StdErr.Write(x) or WScript.StdErr.WriteLine(x) |
| Common Lisp | (setf x (read-line)) | (princ x) or (format t format x) | (princ x *error-output*) or (format *error-output* format x) |
| Scheme (R$^6$RS) | (define x (read-line)) | (display x) or (format #t format x) | (display x (current-error-port)) or (format (current-error-port) format x) |
| ISLISP | (setf x (read-line)) | (format (standard-output) format x) | (format (error-output) format x) |
| Pascal | read(x); or readln(x); | write(x); or writeln(x); | write(stderr, x); or writeln(stderr, x); |
| Visual Basic | Input« prompt,» x | Print x or ? x | — |
| Visual Basic .NET | x = Console.Read or x = Console.ReadLine | Console.Write(«format,»x) or Console.WriteLine(«format, »x) | Console.Error.Write(«format, »x) or Console.Error.WriteLine(«format, »x) |
| Xojo | x = StandardInputStream.Read or x = StandardInputStreame.ReadLine | StandardOutputStream.Write(x) or StandardOutputStream.WriteLine(x) | StdErr.Write(x) or StdErr.WriteLine(x) |
| Python 2.x | x = raw_input(«prompt») | print x or sys.stdout.write(x) | print >> sys.stderr, x or sys.stderr.write(x) |
| Python 3.x | x = input(«prompt») | print(x«, end=""») | print(x«, end=""», file=sys.stderr) |
| S-Lang | fgets (&x, stdin) | fputs (x, stdout) | fputs (x, stderr) |
| Fortran | READ(*,format) variable names or READ(INPUT_UNIT,format) variable names | WRITE(*,format) expressions or WRITE(OUTPUT_UNIT,format) expressions | WRITE(ERROR_UNIT,format) expressions |
| Forth | buffer length ACCEPT ( # chars read ) KEY ( char ) | buffer length TYPE char EMIT | — |
| PHP | $x = fgets(STDIN); or $x = fscanf(STDIN, format); | print x; or echo x; or printf(format, x); | fprintf(STDERR, format, x); |
| Perl | $x = <>; or $x = <STDIN>; | print x; or printf format, x; | print STDERR x; or printf STDERR format, x; |
| Raku | $x = $*IN.get; | x.print or x.say | x.note or $*ERR.print(x) or $*ERR.say(x) |
| Ruby | x = gets | puts x or printf(format, x) | $stderr.puts(x) or $stderr.printf(format, x) |
| Windows PowerShell | $x = Read-Host«« -Prompt» text»; or $x = [Console]::Read; or $x = [Console]::ReadLine | x; or Write-Output x; or echo x | Write-Error x |
| OCaml | let x = read_int or let str = read_line or Scanf.scanf format (fun x ... -> ...) | print_int x or print_endline str or Printf.printf format x ... | prerr_int x or prerr_endline str or Printf.eprintf format x ... |
| F# | let x = System.Console.ReadLine | printf format x ... or printfn format x ... | eprintf format x ... or eprintfn format x ... |
| Standard ML | val str = TextIO.inputLIne TextIO.stdIn | print str | TextIO.output (TextIO.stdErr, str) |
| Haskell (GHC) | x <- readLn or str <- getLine | print x or putStrLn str | hPrint stderr x or hPutStrLn stderr str |
| COBOL | ACCEPT x | DISPLAY x | |
* ^a ALGOL 68 additionally as the "unformatted" transput routines: read, write, get, and put.
* ^b gets(x) and fgets(x, length, stdin) read unformatted text from stdin. Use of gets is not recommended.
* ^c puts(x) and fputs(x, stdout) write unformatted text to stdout.
* ^d fputs(x, stderr) writes unformatted text to stderr
* ^e INPUT_UNIT, OUTPUT_UNIT, ERROR_UNIT are defined in the ISO_FORTRAN_ENV module.

## Reading command-line arguments

| | Argument values | Argument counts | Program name / Script name |
| Ada | Argument (n) | Argument_Count | Command_Name |
| C (C99) | argv[n] | argc | first argument |
| Objective-C | argv[n] | argc | first argument |
| C++ | argv[n] | argc | first argument |
| C# | args[n] | args.Length | Assembly.GetEntryAssembly.Location; |
| Java | args[n] | args.length | |
| D | args[n] | args.length | first argument |
| JavaScript Windows Script Host implementation | WScript.Arguments(n) | WScript.Arguments.length | WScript.ScriptName or WScript.ScriptFullName |
| Go | os.Args[n] | len(os.Args) | first argument |
| Rust | std::env::args.nth(n) std::env::args_os.nth(n) | std::env::args.count std::env::args_os.count | std::env::args.next std::env::args_os.next |
| Swift | Process.arguments[n] or Process.unsafeArgv[n] | Process.arguments.count or Process.argc | first argument |
| Common Lisp | ? | ? | ? |
| Scheme (R$^6$RS) | (list-ref (command-line) n) | (length (command-line)) | first argument |
| ISLISP | — | — | — |
| Pascal | ParamStr(n) | ParamCount | first argument |
| Visual Basic | Command | — | App.Path |
| Visual Basic .NET | CmdArgs(n) | CmdArgs.Length | [Assembly].GetEntryAssembly.Location |
| Xojo | System.CommandLine | (string parsing) | Application.ExecutableFile.Name |
| Python | sys.argv[n] | len(sys.argv) | first argument |
| S-Lang | __argv[n] | __argc | first argument |
| Fortran | DO i = 1,argc CALL GET_COMMAND_ARGUMENT (i,argv(i)) ENDDO | argc = COMMAND_ARGUMENT_COUNT | CALL GET_COMMAND_ARGUMENT (0,progname) |
| PHP | $argv[n] | $argc | first argument |
| Bash shell | $n ($1, $2, $3, ...) $@ (all arguments) | $# | $0 |
| Perl | $ARGV[n] | scalar(@ARGV) | $0 |
| Raku | @*ARGS[n] | @*ARGS.elems | $PROGRAM_NAME |
| Ruby | ARGV[n] | ARGV.size | $0 |
| Windows PowerShell | $args[n] | $args.Length | $MyInvocation.MyCommand.Name |
| OCaml | Sys.argv.(n) | Array.length Sys.argv | first argument |
| F# | args.[n] | args.Length | Assembly.GetEntryAssembly.Location |
| Standard ML | List.nth (CommandLine.arguments, n) | length (CommandLine.arguments) | CommandLine.name |
| Haskell (GHC) | do { args <- System.getArgs; return length args !! n} | do { args <- System.getArgs; return length args} | System.getProgName |
| COBOL | | | — |
* ^a In Rust, std::env::args and std::env::args_os return iterators, std::env::Args and std::env::ArgsOs respectively. Args converts each argument to a String and it panics if it reaches an argument that cannot be converted to UTF-8. ArgsOs returns a non-lossy representation of the raw strings from the operating system (std::ffi::OsString), which can be invalid UTF-8.
* ^b In Visual Basic, command-line arguments are not separated. Separating them requires a split function Split(string).
* ^c The COBOL standard includes no means to access command-line arguments, but common compiler extensions to access them include defining parameters for the main program or using ACCEPT statements.

## Execution of commands

| | Shell command | Execute program | Replace current program with new executed program |
| Ada | Not part of the language standard. Commonly done by compiler provided packages or by interfacing to C or POSIX. | Not part of the language standard. Commonly done by compiler provided packages or by interfacing to C or POSIX. | Not part of the language standard. Commonly done by compiler provided packages or by interfacing to C or POSIX. |
| C | system("command"); | | execl(path, args); or execv(path, arglist); |
| C++ | system("command"); | | execl(path, args); or execv(path, arglist); |
| Objective-C | system("command"); | [NSTask launchedTaskWithLaunchPath:(NSString *)path arguments:(NSArray *)arguments]; | |
| C# | | System.Diagnostics.Process.Start(path, argstring); | |
| F# | | System.Diagnostics.Process.Start(path, argstring); | |
| Go | | exec.Run(path, argv, envv, dir, exec.DevNull, exec.DevNull, exec.DevNull) | os.Exec(path, argv, envv) |
| Visual Basic | Interaction.Shell(command «, WindowStyle» «, isWaitOnReturn») | | |
| Visual Basic .NET | Microsoft.VisualBasic.Interaction.Shell(command «, WindowStyle» «, isWaitOnReturn») | System.Diagnostics.Process.Start(path, argstring) | |
| Xojo | Shell.Execute(command «, Parameters») | FolderItem.Launch(parameters, activate) | — |
| D | std.process.system("command"); | | std.process.execv(path, arglist); |
| Java | | Runtime.exec(command); or new ProcessBuilder(command).start; | |
| JavaScript Windows Script Host implementation | WScript.CreateObject ("WScript.Shell").Run(command «, WindowStyle» «, isWaitOnReturn»); | WshShell.Exec(command) | |
| Common Lisp | (uiop:run-program command) | | |
| Scheme | (system command) | | |
| ISLISP | — | — | — |
| Pascal | system(command); | | |
| OCaml | Sys.command command, Unix.open_process_full command env (stdout, stdin, stderr),... | Unix.create_process prog args new_stdin new_stdout new_stderr, ... | Unix.execv prog args or Unix.execve prog args env |
| Standard ML | OS.Process.system command | Unix.execute (path, args) | Posix.Process.exec (path, args) |
| Haskell (GHC) | System.system command | System.Process.runProcess path args ... | Posix.Process.executeFile path True args ... |
| Perl | system(command) or $output = `command` or $output = qx(command) | | exec(path, args) |
| Ruby | system(command) or output = `command` | | exec(path, args) |
| PHP | system(command) or $output = `command` or exec(command) or passthru(command) | | |
| Python | os.system(command) or subprocess.Popen(command) | subprocess.call(["program", "arg1", "arg2", ...]) | os.execv(path, args) |
| S-Lang | system(command) | | |
| Fortran | CALL EXECUTE_COMMAND_LINE (COMMAND «, WAIT» «, EXITSTAT» «, CMDSTAT» «, CMDMSG») | | |
| Windows PowerShell | [Diagnostics.Process]::Start(command) | «Invoke-Item »program arg1 arg2 ... | |
| Bash shell | output=`command` or output=$(command) | program arg1 arg2 ... | |
^a Fortran 2008 or newer.