Php filter_var function
<p>I know that the function filter_var() returns true or false but when I mean if I have</p>

<pre><code>if( filter_var( $value , FILTER_VALIDATE_INT ) )
    echo 'value is sanitized';
else 
    echo 'value is sanitized';
</code></pre>

<p>Can anyone explain when this function returns true or false?</p>
