Using the apply method to implement object inheritance in javascript

Copy the code code as follows:

<script type="text/javascript">

//Use the apply method to implement object inheritance

function Parent(username) {

this.username = username;

this.sayHello = function() {

alert(this.username);

}

}

function Child(username, password) {

Parent.apply(this, new Array(username));

//Same as below

//Parent.apply(this, [username]);

this.password = password;

this.sayWorld = function() {

alert(this.password);

}

}

var parent = new Parent("zhangsan");

var child = new Child("lisi", "123");

parent.sayHello();

child.sayHello();

child.sayWorld();

</script>