Comma delimited string to multi-dimensional array

<?php
$comma_string = 'this,is,a,comma,string,with,some,content';
$exploded = explode(',', $comma_string);

$multi_array = array();
while($exploded) {
   $multi_array[array_shift($exploded)] = array_shift($exploded);
}
var_dump($multi_array);