Javascript 继承机制试用
简述：
关于javascript 继承的实现
知识点：
1. 继承父类的方法
2. 使用prototype定义类的成员函数
3. 子类重写父类的成员函数
测试：
1.继承父类，包括父类的成员函数
代码：
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>test the inheritance</title>
</head>
<body>
<script type="text/javascript">
/*************************Person class*************************/
var Person = function(name,age){
this.name = name;
this.age = age;
};
Person.prototype.getInfo = function(){
return "name: " + this.name + ", age: " + this.age;
};
/*************************Employee class*************************/
// inherit Person class
var Employee = function(name,age,job){
Person.call(this,name,age);
this.job = job;
}
//if Employee wants to inherit Person
//the prototype should be the father
Employee.prototype = new Person();
/*****************************test********************************/
var employee = new Employee("Peter",21,"worker");
document.write(employee.getInfo());
</script>
</body>
</html>
输出：
name: Peter, age: 20
2.继承父类后，重写父类成员函数
重写父类的getInfo（）函数
代码：
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>test the inheritance</title>
</head>
<body>
<script type="text/javascript">
/*************************Person class*************************/
var Person = function(name,age){
this.name = name;
this.age = age;
};
Person.prototype.getInfo = function(){
return "name: " + this.name + ", age: " + this.age;
};
/*************************Employee class*************************/
// inherit Person class
var Employee = function(name,age,job){
//invoke the constructor of base class
Person.prototype.constructor.call(this,name,age);
this.job = job;
}
//if Employee wants to inherit Person
//the prototype should be the father
Employee.prototype = new Person();
//overwrite member function in Person
Employee.prototype.getInfo = function(){
return "name: " + this.name + ", age: " + this.age +", job: " + this.job;
}
/*****************************test********************************/
var employee = new Employee("Peter",21,"worker");
document.write(employee.getInfo());
</script>
</body>
</html>
输出：
name: Peter, age: 21, job: worker