你这几个判断，我机器上的输出都是true啊，环境时node -v =>v6.1.0
测试代码：
"use strict";


function Base(name)
{
    this.name=name
}

function Derived(name,age)
{
    //Base.call(this,name);
    this.age=age
}

Derived.prototype=new Base("aaa")

var d1=new Derived("name1",22);
var d2=new Derived("name2",23);

console.log("name" in d1)
console.log("name" in d2)
console.log("name" in Derived.prototype)
console.log("name" in Object.getPrototypeOf(d1))
console.log("name" in Object.getPrototypeOf(d2))


【 在 XeCycle (据说是小 X) 的大作中提到: 】
: "name" in d1 -> true
: "name" in d2 -> true
: "name" in Derived.prototype -> false
: ...................
--
FROM 159.226.171.*