<?php
		$arraya = explode(', ' , 'value1, value2, value3');
		$arrayb = array( 'value3', 'value1', 'value2' );
		print_r( array_diff( $arraya , $arrayb ) );

		$arraya = explode(', ' , 'value1, value2, value3, value999');
		$arrayb = array( 'value3', 'value1', 'value2' );
		print_r( array_diff( $arraya , $arrayb ) );
// your code goes here