隐式迭代的原理

function Persion() {
  this.items = [];
  this.click = function(f){
   for(var i =0; i< this.items.length ;i++){
    this.items[i].click = f;
   }
   this.click = f;
  };
}

var p1 = new Persion();
var p2 = new Persion();

var p = new Persion();
p.items.push(p1);
p.items.push(p2);