Javascript设计模式系列三

浏览数：21 / 时间：2015年06月08日

　　继承，一个类或对象继承另一个类或对象的三种方法。类式继承、原型式继承、掺元类。

　　一、类式继承，原型链、Extend函数。

 <script type="text/javascript">
        
        ////定义Person类
        var Person = function (name) {
            this.name = name;
        };

        Person.prototype.getName = function () {
            return this.name;
        };

        ////原型链
        function Author(name, books) {
            Person.call(this, name);
            this.books = books;
        };

        Author.prototype = new Person();
        Author.prototype.constructor = Author;
        Author.prototype.getBooks = function () {
            return this.books;
        };

        var author = new Author("XX", "books")
        alert(author.getName()+author.getBooks());

        ////Extend函数
        function Extend(subClass,superClass) {
            var F = function () { };
            F.prototype = superClass.prototype;
            subClass.prototype = new F();
            subClass.prototype.constructor = subClass;
        };

        function Author(name, books) {
            Person.call(this, name);
            this.books = books;
        }

        Extend(Author, Person);

        Author.prototype.getBooks = function () {
            return this.books;
        };

        var author = new Author("X", "books")
        alert(author.getName() + author.getBooks());

    </script>

　　二、原型式继承。使用原型式继承时，并不需要用类来定义对象的结构，只需直接创建一个对象即可。这个对象随后可以被新的对象重用，该对象被称为原型对象。Clone函数。

 <script type="text/javascript">

        ////Clone函数
        function clone(object) {
            function F() { };
            F.prototype = new object();
            return new F();
        };

        ////定义Person类
        var Person = function () {
            this.name = ‘default name‘;
            this.getName = function () {
                return this.name;
            }
        };

        ////实例化
        var Author = clone(Person);
        alert(Author.name);
        Author.name = "原型式继承";
        alert(Author.name);
        alert(Author.getName());
 
    </script>