JavaScript Comments

Comments are a valuable tool for improving code readability and aiding collaboration among developers.

1. Single-Line Comments

Single-line comments are preceded by two forward slashes (//). They are used for adding comments on a single line.

// This is a single-line comment
let variable = 42;  // Another single-line comment

2. Multi-Line Comments

Multi-line comments start with /* and end with */. They are used for adding comments that span multiple lines.

/*
  This is a multi-line comment.
  It can be used for longer explanations or comments.
*/
let result = calculate(); // Function call

Best Practices for Using Comments

Be Clear and Concise:

• Write comments that are easy to understand and provide clarity.

Update Comments Regularly:

• Keep comments up-to-date with the code. Outdated comments can be misleading.

Avoid Redundant Comments:

• Only add comments when necessary. Code should be self-explanatory whenever possible.

Use Comments for Complex Logic:

• Add comments to explain complex algorithms, tricky parts of the code, or any non-obvious behavior.

Don't Comment Obvious Code:

• Avoid commenting on things that are obvious from the code itself. For example, i++ // increment i is unnecessary.

Follow a Consistent Style:

• Maintain a consistent style for commenting throughout the codebase.

Example

// Function to calculate the square of a number
function square(number) {
  return number * number;
}

/*
  This is a block comment providing additional information.
  It spans multiple lines.
*/
let result = square(7);  // Calling the square function with the number 7