Javascript 面向对象编程继承方法二（Call继承）

function Person(name,age,position){    
        this.name = name;   
        this.age = age;   
        this.position = position;   
  
        this.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);
    }   
  
    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]