COBOL - Basic Syntax

'Characters' are lowest in the hierarchy and they cannot be divided further. The COBOL Character Set includes 78 characters which are shown below −
A-Z
Alphabets(Upper Case)
a-z
Alphabets (Lower Case)
0-9
Numeric
 
Space
+
Plus Sign
-
Minus Sign or Hyphen
*
Asterisk
/
Forward Slash
$
Currency Sign
,
Comma
;
Semicolon
.
Decimal Point or Period
"
Quotation Marks
(
Left Parenthesis
)
Right Parenthesis
>
Greater than
<
Less than
:
Colon
'
Apostrophe
=
Equal Sign
The source program of COBOL must be written in a format acceptable to the compilers. COBOL programs are written on COBOL coding sheets. There are 80 character positions on each line of a coding sheet.
Character positions are grouped into the following five fields −
The following example shows a COBOL coding sheet −
000100 IDENTIFICATION DIVISION.                                         000100
000200 PROGRAM-ID. HELLO.                                               000101
000250* THIS IS A COMMENT LINE                                          000102
000300 PROCEDURE DIVISION.                                              000103
000350 A000-FIRST-PARA.                                                 000104
000400     DISPLAY “Coding Sheet”.                                      000105
000500 STOP RUN.                                                        000106
JCL to execute the above COBOL program −
//SAMPLE JOB(TESTJCL,XXXXXX),CLASS = A,MSGCLASS = C
//STEP1 EXEC PGM = HELLO
When you compile and execute the above program, it produces the following result −
Coding Sheet

Character strings are formed by combining individual characters. A character string can be a
Comment,
Literal, or
COBOL word.
All character strings must be ended with separators. A separator is used to separate character strings.
Frequently used separators − Space, Comma, Period, Apostrophe, Left/Right Parenthesis, and Quotation mark.
A comment is a character string that does not affect the execution of a program. It can be any combination of characters.
There are two types of comments −
A comment line can be written in any column. The compiler does not check a comment line for syntax and treats it for documentation.
Comment entries are those that are included in the optional paragraphs of an Identification Division. They are written in Area B and programmers use it for reference.
The text highlighted in Bold are the commented entries in the following example −
000100 IDENTIFICATION DIVISION.                                         000100
000150 PROGRAM-ID. HELLO.                                               000101 
000200 AUTHOR. TUTORIALSPOINT.                                          000102
000250* THIS IS A COMMENT LINE                                          000103
000300 PROCEDURE DIVISION.                                              000104
000350 A000-FIRST-PARA.                                                 000105  
000360/ First Para Begins - Documentation Purpose                       000106
000400     DISPLAY “Comment line”.                                      000107
000500 STOP RUN.                                                        000108
JCL to execute above COBOL program −
//SAMPLE JOB(TESTJCL,XXXXXX),CLASS = A,MSGCLASS = C
//STEP1 EXEC PGM = HELLO
When you compile and execute the above program, it produces the following result −
Comment Line

Literal is a constant that is directly hard-coded in a program. In the following example, "Hello World" is a literal.
PROCEDURE DIVISION.
DISPLAY 'Hello World'.
There are two types of literals as discussed below −
Alphanumeric Literals are enclosed in quotes or apostrophe. Length can be up to 160 characters. An apostrophe or a quote can be a part of a literal only if it is paired. Starting and ending of the literal should be same, either apostrophe or quote.
Example
The following example shows valid and invalid Alphanumeric Literals −
Valid:
   ‘This is valid’
   "This is valid"
   ‘This isn’’t invalid’

Invalid:
   ‘This is invalid”
   ‘This isn’t valid’
A Numeric Literal is a combination of digits from 0 to 9, +, –, or decimal point. Length can be up to 18 characters. Sign cannot be the rightmost character. Decimal point should not appear at the end.
Example
The following example shows valid and invalid Numeric Literals −
Valid:
   100
   +10.9
   -1.9

Invalid:
   1,00
   10.
   10.9-
COBOL Word is a character string that can be a reserved word or a user-defined word. Length can be up to 30 characters.
User-defined words are used for naming files, data, records, paragraph names, and sections. Alphabets, digits, and hyphens are allowed while forming userdefined words. You cannot use COBOL reserved words.
Reserved words are predefined words in COBOL. Different types of reserved words that we use frequently are as follows −
Keywords like ADD, ACCEPT, MOVE, etc.
Keywords like ADD, ACCEPT, MOVE, etc.
Special characters words like +, -, *, <, <=, etc
Special characters words like +, -, *, <, <=, etc
Figurative constants are constant values like ZERO, SPACES, etc. All the constant values of figurative constants are mentioned in the following table.
Figurative constants are constant values like ZERO, SPACES, etc. All the constant values of figurative constants are mentioned in the following table.
HIGH-VALUES
One or more characters which will be at the highest position in descending order.
LOW-VALUES
One or more characters have zeros in binary representation.
ZERO/ZEROES
One or more zero depending on the size of the variable.
SPACES
One or more spaces.
QUOTES
Single or double quotes.
ALL literal
Fills the data-item with Literal.

    12 Lectures 
     2.5 hours 

 Nishant Malik

    33 Lectures 
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 Craig Kenneth Kaercher
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