js中寄生组合式继承的疑问？

Question

function object(o){    function F(){}    F.prototype = o;    return new F();}function inheritPrototype(subType, superType){    var prototype = object(superType.prototype);    prototype.constructor = subType;    subType.prototype = prototype;}function SuperType(name){    this.name = name;    this.clolors = ['red', 'blue', 'green'];}SuperType.prototype.sayName = function (){    alert(this.name);}function SubType(name, age){    SuperType.call(this, name);    this.age = age;}SubType.prototype = inheritPrototype(subType, superType);SuperType.prototype.sayAge = function (){    alert(this.age);}这里是高程里实现寄生组合式继承的方法，我有一点想不明白：function object(o){    function F(){}    F.prototype = o;    return new F();}function inheritPrototype(subType, superType){    var prototype = object(superType.prototype);    prototype.constructor = subType;    subType.prototype = prototype;}这两个函数实现的效果和subType.prototype.__proto__ = superType.prototype有什么区别呢？如果没有区别，为什么非要用两个函数来实现？

Answer 1

高级程序设计中没有定义object函数吧，inheritPrototype中调用的是Object构造函数，返回一个新对象，具有和superType.prototype中一样的属性和方法，这样一来，每个实例继承的原型就不指向同一个原型对象（但是都是通过superType.prototype创建的副本）