Introduction to C++ | Comments

C++ Comments

In C++, comments are used to explain the code and make it easier for humans to understand. They are ignored by the compiler and do not affect the program's execution. Comments are an essential part of writing clean and maintainable code.

What is a Comment?

A comment is a part of the code that is not executed but is intended to provide explanations or notes for anyone reading the code. It can describe the purpose of the code, clarify complex logic, or remind developers of important considerations.

Types of Comments in C++

C++ supports two types of comments:

• Single-line comments: These comments are used for brief notes or explanations on a single line.
• Multi-line comments: These comments span multiple lines and are typically used for longer explanations or for temporarily disabling a block of code.

Syntax of Comments

The syntax for the two types of comments is as follows:

        // This is a single-line comment
                    

        /* This is a 
           multi-line comment
           that spans multiple lines */
                    

Example of Single-line and Multi-line Comments

Here is an example demonstrating both types of comments:

        #include <iostream>
        using namespace std;
        
        int main() {
            int a = 5;  // This is a single-line comment
        
            /* This is a multi-line comment
               explaining the next block of code. */
            int b = 10;
        
            cout << "The sum of a and b is: " << (a + b) << endl;
        
            return 0;
        }
                    

Output

Explanation of Code

In the code above, the first comment explains the variable a, while the multi-line comment provides additional context for the variable b. The comments are ignored by the compiler, so they do not affect the output of the program. The final line of the code prints the sum of a and b.

When to Use Comments

Comments should be used wisely in your code. They can help make your code more understandable for others (or yourself) in the future. Here are some best practices:

• Use comments to explain complex logic or algorithms.
• Comment sections of code that you may revisit later.
• Write comments for functions to describe their purpose, input parameters, and return values.
• Avoid over-commenting obvious code. Your code should be as self-explanatory as possible, and comments should be used only where necessary.

Pro Tip: