What are the five basic elements of a C++ program
Tags: codin, programming, python, c
Published: 2022-11-22 07:23:57

Do you want to learn about the basics of C++, with the essential elements?
 
But before we start, here is a bit of an overview about the basics of C++. C++ is a general processing programming language which is based on C language. It was developed by Bjarne Stroustrup to give more access and freedom to the programmers with their programmes and code. 

This article outlines the 5 basic elements of C++ programs, which are standard library, variable, statements, expressions, and functions.

We will tell you how these elements work in a C++ program. The more you understand the elements of a C++ program, the more easily you will be able to run the program without any errors.

## 1. Standard Library

The standard library [basics of C++ program](https://www.codingninjas.com/codestudio/guided-paths/basics-of-c) incorporate all standard libraries, with small changes and additions to support type safety.

The standard library of C++ is categorised into two types, the standard function library and the object-oriented class library.

**Standard library function-** The standard function library consists of stand-alone and general-purpose functions that are not considered part of the class. This function library is inherited from the C language. 

The standard function library of C++ is split into the following categories, as same as the basics of python.

=> Dynamic allocation
=> Date, time, and localization
=> Wide character functions
=> Character and string handling
=> I/O
=> Miscellaneous
=> Mathematical

**Object-oriented library function –** It is the collection of associated functions and classes in C++. The object-oriented library function basics of C++ define the complete set of classes that give support to many activities, like I/O strings, numeric processing, etc

=> The numeric class
=> The string class
=> The STL allocators
=> The STL iterators
=> The STL algorithms, etc 

## 2.Variables

The name of the variable in C++ is provided to the memory location. It is considered a basic storage unit in the program.

=> The variable values stored in the C++ program can change with the program's execution, as they are changed in the basics of python.
=> All the operations are done with variable impacts on the memory location
=> All the variables should be declared before use in a C++ program.

**Rules to declare variables in C++ program**

=> The variable name consists of the digits, letters, and underscores
=> The variable name is case sensitive; for example, the ARR and arr are two different variable names
=> The variable name does not consist of any special characters, and whitespaces
=> All the names of variables must start with an alphabet letter or underscore
=> Using any keywords in C++ as a variable name is not allowed.

## Difference between the variable definition and declaration

The definition of a variable is the part where the memory location and values are assigned to a variable. On the other hand, the variable declaration refers to the part where the variable is always first declared or defined before using a variable.

In many cases of the basics of C++ programs, variable definition and declaration have come together.

## 3.C++ expressions

Expressions in C++ is the combination of variables, operators, and constants. Based upon the type of operand used in the expression or results come after evaluating the expression. Here are the different types of expressions used in C++ programs.

**Constant expressions**

The expressions that only compromise the constant values are known as constant expressions. Examples of C++ constant expressions are “a,” 20, etc.

**Integral expressions**

The expression in C++ that gives the integral output values after performing every type of conversion is known as an integral expression.

**Float expressions**

The C++ expressions that give the float point values as output after performing different types of conversions are known as float expressions.

**Boolean expressions or relational expressions**

The expressions that give the Boolean type values, either true or false, are known as Boolean or relationship expressions. This type of expression is also seen in the basics of python.

**Logical expressions**

The expressions in C++ that give the Boolean type values after mixing two or more Boolean type expressions are known as logical expressions.

**Bitwise expressions**

The C++ expressions that help to manipulate the data at the level bit are known as bitwise expressions. For example, b<<2 and a>>4 are considered bitwise expressions.

**Pointer expressions**

The pointer expressions provide the proper address values as output. For instance, the &x, -ptr, and ptr are known as pointer expressions. X is a data type variable, and ptr is called a pointer.

## 4.C++ statements

The statements in C++ are considered standard program elements that help to control how and in what order objects are manipulated. There are different types of statements used in C++ programs.

**Expression statement**

The statement gives the expressions for return values or side effects of the C++ program, which are known as expression statements.

**Null statements**

The null type statement is needed in C++ programs where the statement is needed by C++ syntax, but no action takes place.

**Compound statement**

Compound statements in the basics of C++ are groups of statements that are enclosed in curly braces. These statements are used in the case of a single statement in the program.

**Selection statement**

These statements in C++ do tests and then execute one part of code if the test evaluates to non zero. They may also execute the other code if test evaluations are false.

**Iteration statement**

These statements give the repeated block execution of code until the specific criteria are not fulfilled.

**Jump statement**

These statements are responsible for transferring control instantly to another location kept in function or back control from function.

**Declaration statement**

The declaration statement helps to introduce the name into the C++ program.

## 5.Functions in C++

The function used in the basics of C++ programming languages is also known as subroutines or procedures in other programming languages. You must create the function if you want to run the program or perform the C++ task.

You can call the function multiple times in a C++ program. It offers you code usability and modularity.

**Code reusability**

You can quickly call too many times after creating the C++ functions. It means you can write the program's code sparingly.

**Code optimization**

Functions in C++ help to make the code optimised. It means you can write only a little code or much coding. The best thing is that the function allows you to write the logic one time and use it many times again. 
 

## Conclusion

In a nutshell, all the elements mentioned earlier of the basics of C++, the work is different. It is important to understand every element, to make error-free C++ programs.