以下為JS寄生組合繼承的實現方式         function Super(b){             this.b = b;             this.fun = function(){}         }         Super.prototype.c = function(){console.log(1111)}         function Foo(a,b){             this.a = a;             Super.call(this,b);         }         var f = new Function();         f.prototype = Super.prototype;         Foo.prototype = new f();         var foo1 = new Foo(1,2);為什么不直接用以下方式，更簡潔而且能實現同樣的效果        function Super(b){             this.b = b;             this.fun = function(){}         }         Super.prototype.c = function(){console.log(1111)}         function Foo(a,b){             this.a = a;             Super.call(this,b);         }         Foo.prototype = Super.prototype;         var foo1 = new Foo(1,2);