Using an array as needles in mb_strpos

functions.php

<?php
if( ! function_exists( 'mb_strpos' ) ){
  function mb_strpos( $haystack, $needles, $offset=0 ){
    return strpos( $haystack, $needle, $offset );
  }
}

function mb_strposa( $haystack, $needles = array(), $offset=0 ) {
  $chr = array();
  foreach( $needles as $needle ){
    $res = mb_strpos( $haystack, $needle, $offset );
    if( $res !== false ) $chr[ $needle ] = $res;
  }
  if( empty( $chr ) ){
    return false;
  }

  return mb_min( $chr );
}