Simple example of getting Key from PHP array based on value

/**
* Get Key based on the value of php array
* by bbs.it-home.org
*/
function getKey($arr, $value) {
 if(!is_array($arr)) return null;
 foreach($arr as $k =>$v) {
  $return = getKey($v, $value);
  if($v == $value){
   return $k;
  }
  if(!is_null($return)){
   return $return;
  }
 }
}