🟢 Foundation · Lesson 06

Comments in C++

What is Comments in C++?

Comments in C++
Comments are notes written inside a program for human readers. The compiler ignores comments. Good comments explain purpose, logic and important decisions.

Level
🟢 Beginner – C++ Foundation

Example File
comments.cpp

Main Focus
Concept + syntax + practical C++ program

Why should you learn this?

It helps you write correct and readable C++ programs.
It is used repeatedly in school practicals, projects and competitive programming.
It builds the base for advanced topics such as OOP, STL and data structures.

Important Terms

Term	Meaning / Use
single-line comment	Single-line comment used in Comments in C++ programming.
multi-line comment	Multi-line comment used in Comments in C++ programming.
documentation	Documentation used in Comments in C++ programming.

Syntax / Pattern

Use // for one-line comments and /* ... */ for multi-line comments.

Example Program

#include <iostream>
using namespace std;

int main() {
    // This prints a message
    cout << "Learning comments";
    return 0;
}

Expected Output

Learning comments

Program Explanation

The line beginning with // is ignored by compiler.
The cout line actually prints the output.

Exam Tip: In C++ practical answers, write the logic first, then the program, then expected output. For theory, always include one suitable example.

Where will you use it?

explaining formulas
documenting functions
making code readable

Common Mistakes

Writing too many useless comments.
Using comments to hide errors instead of fixing them.

Practice Tasks

Add comments to a marks calculation program.
Explain when multi-line comments are useful.

Summary

Comments in C++ is an important C++ topic. Learn the definition, understand the syntax, run the example program and then solve the practice tasks to make the concept strong.