Javascript 面向对象编程继承方法四(原型继承)

function Person(name,age,position){      
      this.name = name;      
      this.age = age;      
      this.position = position;        
 }      
 
 Person.prototype.displayInfo = function(){      
       alert("[Name: "+ this.name +"]  [Age: "+this.age+"]  [position: "+this.position+"]");      
 }     
  
 function Programmer(name,age,position){      
        this.tempObject = Person;     //声明临时指针指向父类     
        this.tempObject(name,age,position);        
      /*    
         相当于调用函数Person(...),调用父类构造函数,没有new,this指向子类，  
         进而有：this.displayInfo = function()    
          相当于：this.person = function(){    
                                this.display = function()                             
                         }    
      */     
       delete this.tempObject;   //删除临时指针,防止通过tempObject引用覆盖超类Person的属性和方法     
                // Person.call(this , name,age,position);   
                // Person.apply(this ,new Array(name,age,position));
 }      
  
Programmer.prototype = new Person();   
  
 var oBpmProgrammer = new Programmer("Kevin",24,"BPM Programmer");      
 var oBopReportDeveloper = new Programmer("Witkey",25,"BOP Report Developer");      
 oBpmProgrammer.displayInfo();    //[Name: Kevin] [Age: 24] [position: BPM Programmer]      
 oBopReportDeveloper.displayInfo(); //[Name: Witkey] [Age: 25] [position: BOP Report Developer]  
  
      /*              
        this.tempObject = Person;     //声明临时指针指向父类     
        this.tempObject(name,age,position);       
       delete this.tempObject;   //删除临时指针,防止通过tempObject引用覆盖超类Person的属性和方
法     
        以上三行代码从Person继承name,age,position属性,同理
        Person.call(this , name,age,position);  和Person.apply(this ,new Array(name,age,position));
 
       如果是使用以下方法，还是一样要有：programmer.prototype = new Person();   
               Person.call(this , name,age,position); 或Person.apply(this ,new Array(name,age,position));
 
               programmer.prototype = new Person();   继承原型方法或属性
*/