JavaScript中继承用法实例分析

// define the Person Classfunction Person() {}Person.prototype.walk = function(){ alert ('I am walking!');};Person.prototype.sayHello = function(){ alert ('hello');};// define the Student classfunction Student() { // Call the parent constructor Person.call(this);}// inherit PersonStudent.prototype = new Person();// correct the constructor pointer because it points to PersonStudent.prototype.constructor = Student;// replace the sayHello methodStudent.prototype.sayHello = function(){ alert('hi, I am a student');}// add sayGoodBye methodStudent.prototype.sayGoodBye = function(){ alert('goodBye');}var student = new Student();student.sayHello();student.walk();student.sayGoodBye();// check inheritancealert(student instanceof Person); // true alert(student instanceof Student); // true