javascript继承分为两种：类式继承（原型链、extend函数）、原型式继承（对继承而来的成员的读和写的不对等性、clone函数）。

1. 类式继承-->prototype继承：

    function Person(name){  
        this.name = name;  
    }  
    Person.prototype.getName = function(){  
        return this.name;  
    }
   
    //继承  
    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("zap","javascript程序设计");  
    console.log(author);

2. 类式继承-->extend函数：

    function extend(subClass,superClass){  
        var F = function(){};  
        F.prototype = superClass.prototype;  
        subClass.prototype = new F();  
        subClass.prototype.constructor = subClass;
    subClass.superClass = superClass.prototype;  
    if(superClass.prototype.constructor == Object.prototype.constructor){  
        superClass.prototype.constructor =  superClass;  
    }  
    }
   
    /\*Class Person\*/
   
    function Person(name){  
        this.name = name;  
    }  
    Person.prototype.getName = function(){  
        return this.name;  
    }
   
    function Author(name,books){  
        Author.superClass.constructor.call(this,name);  

   // Person.call(this,name);
   this.books = books;
   }
   extend(Author,Person);
   Author.prototype.getBooks = function(){
   return this.books;
   }

    var author = new Author("zap","javascript程序设计");  
    console.log(author);  
    console.log(author.getName());  
    console.log(author.getBooks());

3. 原型式继承-->clone函数：(原型式继承更能节约内存)

    var Person  ={  
        name:"zap",  
        age:"26",  
        toString:function(){  
            console.log(this.name + "@" + this.age);  
        }  
    }
   
    var author = clone(Person);  
    author.name = "zap";  
    author.toString();
   
    function clone(object){  
        function F(){}  
        F.prototype = object;  
        return new F;  
    }

   附上以类式继承实现的就地编辑demo，原型式方式实现和类式继承方式相差无几，不在此列举。