Comment (computer programming)

In computer programming, a comment is a programmer-readable explanation or annotation in the source code of a computer program. Comments are added to make the source code easier for humans to understand, and are generally ignored by compilers and interpreters during the execution of the program.

The primary purpose of comments is to provide context and clarify the logic of the code, making it more maintainable and understandable for other programmers (including the original author at a later date). Comments can explain the purpose of a particular section of code, how a complex algorithm works, or why a specific decision was made.

Different programming languages have different syntax for indicating comments. Common forms include single-line comments (which typically begin with a special character or sequence of characters that signals the rest of the line is a comment) and multi-line comments (which are delimited by start and end markers that allow comments to span multiple lines).

While comments are essential for code readability, excessive or poorly written comments can be detrimental. Redundant comments that merely repeat what the code already clearly expresses can clutter the code and make it harder to maintain. Good comments should explain why the code is written a certain way, rather than simply describing what the code does.

Best practices for commenting include:

• Explaining the purpose and intent of the code.
• Documenting complex algorithms or data structures.
• Clarifying any potentially confusing or non-obvious code.
• Updating comments whenever the code is modified.
• Avoiding excessive or redundant comments.
• Using clear and concise language.

Well-written comments are a crucial element of good programming style and are vital for collaborative software development.