Structure of a C++ Program

Every C++ program follows a basic structure. Once you understand what each part does, reading and writing C++ code becomes much easier. Let’s look at a simple C++ program and understand it line by line.

Example

#include <iostream>
using namespace std;

int main() {
    cout << "Welcome to CoderMantra!";
    return 0;
}

Program Structure

1. Header File

#include &lt;iostream>

This line includes the iostream header file, which provides input and output features in C++. Without it, you cannot use cout or cin in your program.

2. Namespace

using namespace std;

The std namespace contains many built-in C++ features. Writing using namespace std; allows you to use cout, cin, and other standard library objects without adding std:: before them every time.

3. Main Function

int main()

The main() function is where every C++ program begins execution. When you run a program, the compiler starts executing the code inside this function.

4. Program Statements

cout << "Welcome to CoderMantra!";

This statement displays the text Welcome to CoderMantra! on the screen. Every statement in C++ ends with a semicolon (;).

5. Return Statement

return 0;

The return 0; statement tells the operating system that the program has finished running successfully.

Key Points

Every C++ program starts from the main() function.
The iostream header file is required for input and output.
using namespace std; makes standard library names easier to use.
cout is used to display output on the screen.
Every statement should end with a semicolon (;).

Written by Shubhranshu Shekhar, who has trained 20000+ students in coding.

Nidhi Srivastav