如何确定一个属性是存在原型中还是对象中

function Person(){
    Person.prototype.name = "china";
    Person.prototype.age = 2;
}

var person1 = new Person();

function hasPrototypeProperty(object,name){
    return !object.hasOwnProperty(name) && (name in object)
}

hasPrototypeProperty(person1,"name");  // true
person1.name = "jack";
hasPrototypeProperty(person1,"name");  //false