使用apply方法实现JavaScript对象继承

 
<script type="text/javascript">
// 使用apply方法实现对象继承
function Parent(username) {
this.username = username;
this.sayHello = function() {
alert(this.username);
} 
} 
}
function Child(username, password) {
Parent.apply(this, new Array(username));
// 效果等同于：
// Parent.apply(this, [username]);
this.password = password;
this.sayWorld = function() {
} 
} 
alert(this.password);
var child = new Child("lisi", "123");
}
var parent = new Parent("zhangsan");
var child = new Child("lisi", "123");
parent.sayHello();