JavaScript中继承用法实例分析

本文实例分析了JavaScript中继承的用法。分享给大家供大家参考。具体如下：

// define the Person Class

function Person() {}

Person.prototype.walk = function(){

alert ('I am walking!');

};

Person.prototype.sayHello = function(){

alert ('hello');

};

// define the Student class

function Student() {

// Call the parent constructor

Person.call(this);

}

// inherit Person

Student.prototype = new Person();

// correct the constructor pointer because it points to Person

Student.prototype.constructor = Student;

// replace the sayHello method

Student.prototype.sayHello = function(){

alert('hi, I am a student');

}

// add sayGoodBye method

Student.prototype.sayGoodBye = function(){

alert('goodBye');

}

var student = new Student();

student.sayHello();

student.walk();

student.sayGoodBye();

// check inheritance

alert(student instanceof Person); // true

alert(student instanceof Student); // true

希望本文所述对大家的javascript程序设计有所帮助。