php array_diff usage example

<?php

$array1 = array(&#39;OH&#39;,&#39;CA&#39;,&#39;NY&#39;,&#39;HI&#39;,&#39;CT&#39;);
$array2 = array(&#39;OH&#39;,&#39;CA&#39;,&#39;HI&#39;,&#39;NY&#39;,&#39;IA&#39;);
$array3 = array(&#39;TX&#39;,&#39;MD&#39;,&#39;NE&#39;,&#39;OH&#39;,&#39;HI&#39;);
$diff = array_diff($array1, $array2, $array3);
print_r($intersection);

?>