Remove Multiple Character From string

Remove Multiple word From a string in comma separated String.

<?php

function removeFromString($str, $item) {

    $parts = explode(',', $str);

    while(($i = array_search($item, $parts)) !== false) {

        unset($parts[$i]);

    }

    return implode(',', $parts);

}

$arra ="one,two";

$string ='one,two,three,four';

$array =explode(",",$arra);

foreach($array as $key=>$value)

{

$string= removeFromString($string, $value);

}

echo $string;

?>

OutPut: three,four