Learning PHP, MySQL, JavaScript, and CSS, 2nd Edition

Using Comments

Due to their shared inheritance from the C programming language, PHP and JavaScript share many similarities, one of which is commenting. First there’s the single-line comment, which looks like this:

// This is a comment

This style uses a pair of forward slash characters (//) to inform JavaScript that everything that follows on that line is to be ignored. And then we have multiline comments, which look like this:

/* This is a section
   of multiline comments
   that will not be
   interpreted */

You start a multiline comment with the sequence /* and end it with */. Just remember that you cannot nest multiline comments, so make sure that you don’t comment out large sections of code that already contain multiline comments.