Javascript Array every(callback)

Array.prototype.every = function every(callback) {
 if (this === undefined || this === null) {
  throw new TypeError(this + ' is not an object');
 }

 if (!(callback instanceof Function)) {
  throw new TypeError(callback + ' is not a function');
 }

 var//from   w w w . ja v a 2s . co m
 object = Object(this),
 scope = arguments[1],
 arraylike = object instanceof String ? object.split('') : object,
 length = Number(arraylike.length) || 0,
 index = -1;

 while (++index < length) {
  if (index in arraylike && !callback.call(scope, arraylike[index], index, object)) {
   return false;
  }
 }

 return true;
};