PHP echo vs PHP short tags

Question

Are they equal in safeness? I was informed that using

<?=$function_here?>

was less safe, and that it slows down page load. So I am now strictly biased to using echo.

I just wanted to know the advantages/disadvantages, or are they pretty much the same.

Answer 1

<? and <?= are called short open tags, and are not always enabled (see the short_open_tag directive).

Actually, in the php.ini-production file provided with PHP 5.3.0, they are disabled by default :

$ grep 'short_open' php.ini-production
; short_open_tag
short_open_tag = Off

So, using them in an application you want to distribute might not be a good idea : your application will not work if they are not enabled.

<?php, on the other side, cannot be disabled -- so, it's safest to use this one, even if longer to write.

Except the fact that short open tagas are not necessarily enabled, I don't think there is much of a difference.

Answer 2

Echo is generally just better to use because...

1. It supports good programming style.
2. It can't be turned off in php.ini (short tags can be)
3. Short tags will be removed in PHP 6)

But, they are generally the same. See also:

1. http://stackoverflow.com/questions/200640/are-php-short-tags-acceptable-to-use
2. http://stackoverflow.com/questions/234241/how-are-echo-and-print-different-in-php

Answer 3

So why don't they just remove the option to turn off short open tag and let it be enabled by default.

This is a VERY dangerous move by PHP. The reason being, if you put your existing code that has short tags in it on a PHP6 server and someone views that page, they will get the raw code downloaded to their browser which you can view. This could seriously kill off PHP.