javascript,繼承,封裝

//語法甘露：
        var object =        //定義小寫的object基本類，用於實現最基礎的方法等
        {
                isA: function(aType)     //一個判斷類與類之間以及對象與類之間關係的基礎方法
                {
                        var self = this;
                        while(self)
                        {
                                if (self == aType)
                                    return true;
                                self = self.Type;
                        };
                        return false;
                }
        };
        
        function Class(aBaseClass, aClassDefine)        //創建類的函數，用於聲明類及繼承關係
        {
                function class_()     //創建類的臨時函數殼
                {
                        this.Type = aBaseClass;        //我們給每一個類約定一個Type屬性，引用其繼承的類
                        for(var member in aClassDefine)
                                this[member] = aClassDefine[member];        //複製類的全部定義到當前創建的類
                };
                class_.prototype = aBaseClass;
                return new class_();
        };
        
        function New(aClass, aParams)     //創建對象的函數，用於任意類的對象創建
        {
                function new_()         //創建對象的臨時函數殼
                {
                        this.Type = aClass;        //我們也給每一個對象約定一個Type屬性，據此可以訪問到對象所屬的類
                        if (aClass.Create)
                            aClass.Create.apply(this, aParams);     //我們約定所有類的構造函數都叫Create，這和DELPHI比較相似
                };
                new_.prototype = aClass;
                return new new_();
        };

        //語法甘露的應用效果：        
        var Person = Class(object,            //派生至object基本類
        {
                Create: function(name, age)
                {
                        this.name = name;
                        this.age = age;
                },
                SayHello: function()
                {
                        alert("Hello, I'm " + this.name + ", " + this.age + " years old.");
                }
        });
        
        var Employee = Class(Person,        //派生至Person類，是不是和一般對象語言很相似？
        {
                Create: function(name, age, salary)
                {
                        Person.Create.call(this, name, age);    //調用基類的構造函數
                        this.salary = salary;
                },
                ShowMeTheMoney: function()
                {
                        alert(this.name + " $" + this.salary);
                }
        });

        var BillGates = New(Person, ["Bill Gates", 53]);
        var SteveJobs = New(Employee, ["Steve Jobs", 53, 1234]);
        BillGates.SayHello();
        SteveJobs.SayHello();
        SteveJobs.ShowMeTheMoney();
        
        var LittleBill = New(BillGates.Type, ["Little Bill", 6]);     //根據BillGate的類型創建LittleBill
        LittleBill.SayHello();
        
        alert(BillGates.isA(Person));             //true
        alert(BillGates.isA(Employee));         //false
        alert(SteveJobs.isA(Person));             //true
        alert(Person.isA(Employee));                //false
        alert(Employee.isA(Person));                //true