Javascript Array indexOf(o, index)

Array.prototype.indexOf = Array.prototype.indexOf || function (o, index) {
  var l = this.length;
  for (var i = Math.max(Math.min(index, l), 0) || 0; i < l; i++)
    if (this[i] === o) return i;
  return -1;/*from  w  ww.  j  a  va2s  .  co  m*/
};