JavaScript继承(copy继承)

js_copy_extend.js

//JavaScript继承
//copy继承(call and prototype)
function extend(obj1, obj2){
  for(var attr in obj2){
    obj1[attr] = obj2[attr]; 
  }
}

function Person(name){
  this.name = name;
}

Person.prototype.sayName = function(){
  console.log(this.name);
};

function Student(name, age){
   Person.call(this, name);
   this.age = age;
}

Student.prototype.sayAge = function(){
  console.log(this.age);
};

extend(Student.prototype, Person.prototype);

var s = new Student("hurry", 26);
s.sayName();
s.sayAge();