小编zpz*_*pzp的帖子

该instanceof运营商应该看看样机,不是吗？在对象的原型发生变化后,为什么不改变它的答案？示例如下:

// The .prototype of objects created with 'new MyKlass'
// is MyKlass.prototype
var MyKlass = function(name, age) {
  this.name = name;
  this.age = age;
}

var xx = new MyKlass('xx', 20);
console.log(xx instanceof MyKlass);      // true, OK

xx.prototype = new String('s');
console.log(xx instanceof MyKlass);      // also true, WHY???