Comments in C

Comments in C are non-executable parts of the code used to explain, clarify, or annotate the program.

• They are ignored by the compiler and do not affect the program’s execution.

Types of Comments in C:

1.) Single-line Comments:

• Start with //
• Comment lasts until the end of the line.
• Introduced in C99 standard.

Example:

int x = 10;  // This is a single-line comment

2.) Multi-line Comments:

• Start with /* and end with */
• Can span multiple lines.
• Supported since early C standards.

Example:

/* 
  This is a multi-line comment.
  It can span several lines.
*/
int y = 20;

Purpose of Comments:

• To explain the purpose of code blocks or logic.
• To make code easier to understand and maintain.
• To temporarily disable code during debugging.
• To add documentation.

Rules and Best Practices:

• Comments should be clear and concise.
• Avoid over-commenting trivial code.
• Do not nest multi-line comments (i.e., no /* … /* … */ … */).
• Use comments to explain why something is done, not what (which should be clear from code).