JavaScript compare() method for Array

Array.prototype.compare.js

Array.prototype.compare = function(array) {
  if (!array) {
    return false;
  }
  if (this.length !== array.length) {
    return false;
  }
  for (var i = 0, l = this.length; i < l; i++) {
    if (this[i] instanceof Array && array[i] instanceof Array) {
      if (!this[i].compare(array[i])) {
        return false;
      }
    }
    else if (this[i] !== array[i]) {
      return false;
    }
  }
  return true;
}