Comments

PHP supports 'C', 'C++' and Unix shell-style (Perl style) comments. For example:


<?php

    echo 'This is a test'; // This is a one-line c++ style comment

    /* This is a multi line comment

       yet another line of comment */

    echo 'This is yet another test';

    echo 'One Final Test'; # This is a shell-style comment

?>

The "one-line" comment styles only comment to the end of the line or the current block of PHP code, whichever comes first. This means that HTML code after // ?> WILL be printed: ?> skips out of the PHP mode and returns to HTML mode, and // cannot influence that. If asp_tags configuration directive is enabled, it behaves the same with // %>. However, </script> tag doesn't escape PHP mode in one-line comment.


<h1>This is an <?php # echo 'simple';?> example.</h1>

<p>The header above will say 'This is an example'.</p>

'C' style comments end by the first encountered */. You should be careful not to nest 'C' style comments, which can happen when commenting out large blocks.


<?php

 /* 

    echo 'This is a test'; /* This comment will cause a problem */

 */

?>