/*
   * function： inherit -> 通过圣杯模式来实现继承
   * params：
   *   Target：继承的对象
   *   Origin: 被继承的对象
  */
    function inherit(Target, Origin) {
    
    
      // careate a buffer function
      function Buffer() {
    
    }
      // let the prototype of Buffer point to the instance of Origin
      Buffer.prototype = Origin.prototype
      // let the prototype of Target point to the instance of Buffer   
      Target.prototype = new Buffer()
      // rewrite the constructor 
      Target.prototype.construtor = Target
      // set the superclass
      Target.prototype.super_class = Origin
   }

    function Teacher(){
    
    }
    // 设置原型上的属性
    Teacher.prototype.name = "zhangsan"
    function Student(){
    
    }
    // 调用函数来实现继承
    inherit(Student, Teacher) 
    var s = new Student()
    s.age = 18
    console.log(s);
    console.log(s.name); // zhangsan
    console.log(s.age); // 18

可以看到成功实现了继承，同时Student的原型上的constructor属性值为 Student，而super_class 属性的值为 Teacher。