Javascript Array all(predicate, context)

Array.prototype.all = function (predicate, context) {
  context = context || window;//from  www.  j  a  va2 s . c  o m
  predicate = predicate || Predicate;
  var f = this.every || function (p, c) {
    return this.length == this.where(p, c).length;
  };
  return f.apply(this, [predicate, context]);
};