Comments in JavaScript

Question: How do I insert comments in JavaScript code?

Answer: JavaScript supports three different types of comments:

1. Multiple-line C-style comments. Everything between /* and */ is a comment, for example:

   /* This is a comment */
   /* C-style comments can span
   as many lines as you like,
   as shown in this example */
   

2. One-line comments of C++ style. These comments begin with // and continue up to the next line break:

   // This is a one-line comment
   

3. One-line comments with the HTML comment-opening sequence (<!--). Note that the JavaScript interpreter ignores the closing characters of HTML comments (-->). Consider this example:

   <!-- This is treated as a one-line JS comment
   <!-- It works just like a comment beginning with //
   <!-- --> This is also a one-line JS comment
   <!-- --> because JS ignores the closing characters
   <!-- --> of HTML-style comments
   

   HTML-style comments are not usually found in the middle of JavaScript code. (The // comments are simpler and easier to read.) However, it is strongly recommended to use HTML comments for hiding JavaScript code from old browsers.

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