C++ Comments

Comments

Typically, comments can be used to identify the authors of the program, give the date when the program is written or modified, give a brief explanation of the program, and explain the meaning of key statements in a program. In the programming examples, for the programs that we write, we will not include the date when the program is written, consistent with the standard convention for writing such books. Comments are for the reader, not for the compiler. So when a compiler compiles a program to check for the syntax errors, it completely ignores comments.

Single-Line Comments

Single-line comments begin with "//" and continue until the end of the line. They are used for brief comments or annotations on a single line of code.

Example:

// This is a single-line comment
int x = 5; // Initializing variable x to 5

Multi-Line Comments

Multi-line comments start with "/*" and end with "*/". They can span across multiple lines and are useful for longer explanations or for commenting out blocks of code temporarily.

Example:

/*
This is a multi-line comment
It can span across multiple lines
*/
int y = 10; // Initializing variable y to 10

Why Use Comments?

Code Explanation

Comments help in explaining the logic and purpose of code segments, making it easier for other programmers (and your future self) to understand the code.

Example:

// Calculate the sum of two numbers
int sum = num1 + num2;

Documentation

Comments also serve as documentation, providing insights into the design choices, algorithms used, and any potential pitfalls in the code.

Example:

Debugging and Maintenance

During debugging or when maintaining code, comments can be invaluable in identifying and fixing issues quickly, especially in complex programs.

Example:

Best Practices

Be Clear and Concise: Write comments that are easy to understand and directly relevant to the code they annotate.
Update Regularly: Keep comments up-to-date with code changes to ensure accuracy.
Avoid Over-Commenting: Don't state the obvious; focus on explaining complex or non-intuitive parts of the code.
Use Meaningful Names: Use meaningful variable and function names to reduce the need for excessive comments.

Comments are a powerful tool in programming that aid in code comprehension, documentation, debugging, and maintenance. By using comments effectively, programmers can enhance the clarity and maintainability of their codebase.