PHP Coding Conventions PHP Tags
Example
You should always use <?php ?> tags or short-echo tags <?= ?>. Other variations (in particular, short tags <? ?>) should not be used as they are commonly disabled by system administrators.
When a file is not expected to produce output (the entire file is PHP code) the closing ?> syntax should be omitted to avoid unintentional output, which can cause problems when a client parses the document, in particular some browsers fail to recognise the <!DOCTYPE tag and activate Quirks Mode.
Example of a simple PHP script:
<?php
print "Hello World";
Example class definition file:
<?php
class Foo
{
...
}
Example of PHP embedded in HTML:
<ul id="nav">
<?php foreach ($navItems as $navItem): ?>
<li><a href="<?= htmlspecialchars($navItem->url) ?>">
<?= htmlspecialchars($navItem->label) ?>
</a></li>
<?php endforeach; ?>
</ul>
