Slash /¶

/ is character, used in various situations:

decimal division: 3 / 2
Path separator: /user/php/document.txt
Regex delimiter: /[abc]/i, very frequent but not the only one
Regex escape char: /a\.b/i
Double slash is the marker of a comment: // a comment till the end of the line
With star, /* is a multi line comment: /* */
With double star, /** is a phpdoc comment: /** */
stripslashes() removes slashes used for escaping, in strings
addslashes() adds slashes for escaping, in strings
addcslashes() adds slashes for escaping arbitrary characters

The slash looks like the back-slash character \, though they have very different use.

<?php

    file_get_contents('/tmp/test.txt');

    echo 1234 / 2;

    // Just a comment

?>