PHP: PHP tags - Manual

[edit] Last updated: Fri, 28 Jun 2013

PHP tags

When PHP parses a file, it looks for opening and closing tags, which are <?php and ?> which tell PHP to start and stop interpreting the code between them. Parsing in this manner allows PHP to be embedded in all sorts of different documents, as everything outside of a pair of opening and closing tags is ignored by the PHP parser.

PHP also allows for short tags <? and ?> (which are discouraged because they are only available if enabled with short_open_tag php.ini configuration file directive, or if PHP was configured with the --enable-short-tags option.

If a file is pure PHP code, it is preferable to omit the PHP closing tag at the end of the file. This prevents accidental whitespace or new lines being added after the PHP closing tag, which may cause unwanted effects because PHP will start output buffering when there is no intention from the programmer to send any output at that point in the script.


<?php
echo "Hello world";

// ... more code

echo "Last statement";

// the script ends here with no PHP closing tag

add a note User Contributed Notes PHP tags - [2 notes]

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preda dot vlad at yahoo dot com ¶

3 months ago


So here are the valid ways to open PHP tags:



<?php ?> // standard tags

<? ?> // short tags, need short_open_tag enabled in php.ini

<% %> // asp tags, need asp_tags enabled in php.ini

<script language="php"> </script> // case insensitive



PSR-1 coding standards suggest to only use <?php ?> or <?= ?> (echo short tags) - and no other variations, and PSR-2 suggests to not close the tags in PHP only files.

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-45

akshay dot leadindia at gmail dot com ¶

1 year ago


If you do (accidentally) leave out a newline character after the closing php tag ( '?>' ) then you may see 'Headers Already Sent' errors. So if you are seeing this error in your output, double check the php file for newline characters after the closing tag.

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