What is the usage of ":" in if and else statements?
<p>I saw the following code snippet:</p>

<pre><code>&lt;?php
if(!empty($_POST)): // case I: what is the usage of the :
if(isset($_POST['num']) &amp;&amp; $_POST['num'] != ''):

$num = (int)$_POST['num'];

....

if($rows == 0):
echo 'No';

else: // case II: what is usage of :
echo $rows.'Yes';

endif;
</code></pre>

<p>I would like to know what the usage of ":" in php code is.</p>
