Comments in C++

Comments are an essential part of any programming language as they help in making the code more readable and understandable. In C++, comments are used to add explanatory notes or to disable certain parts of the code. These comments are ignored by the compiler and have no effect on the execution of the program. In this lesson, we'll explore the different types of comments available in C++ and best practices for using them effectively.

Single-line Comments

Single-line comments begin with a double forward slash ( // ) and continue until the end of the line. They are commonly used to add short explanations or annotations to specific lines of code.

// This is a single-line comment

int num = 42; // Initializing a variable

Multi-line Comments

Multi-line comments, also known as block comments, allow you to comment out multiple lines of code. They begin with a forward slash followed by an asterisk ( /* ) and end with an asterisk followed by a forward slash ( */ ). Multi-line comments are useful when you need to temporarily disable or comment out a section of code.

/*
This is a multi-line comment
It can span multiple lines
Useful for commenting out blocks of code
*/

int num = 42;
/*
int num2 = 24;
int sum = num + num2;
*/

Documentation Comments

Documentation comments, also known as Doxygen-style comments, are used to generate documentation for the code. They begin with a double forward slash followed by an exclamation mark ( //! ) or double asterisk ( /** ). These comments are often used to provide detailed explanations of classes, functions, or code snippets.

//! This is a documentation comment for a function
//! It provides information about the purpose, parameters, and return value of the function
int add(int a, int b) {
    return a + b;
}

/**
 * This is a documentation comment for a class
 * It provides information about the class and its member functions
 */
class MyClass {
    // ...
};

Conclusion

Comments play a crucial role in making your code more readable and maintainable. In C++, you can use single-line comments, multi-line comments, and documentation comments to provide explanations, annotations, or to temporarily disable code. Properly used comments can greatly enhance the understandability and collaboration of your codebase. Remember to use comments judiciously and follow best practices to ensure your comments remain helpful and up-to-date.