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This article mainly introduces js how to achieve prototype chain inheritance, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor take you to understand it.

Since we are going to implement inheritance, we first need to have a parent class with the following code:

/ / define an animal class function Animal (name) {/ / attribute this.name = name | | 'Animal'; / / instance method this.sleep = function () {console.log (this.name +' sleeping!') ;}} / / prototype method Animal.prototype.eat = function (food) {console.log (this.name + 'eating:' + food);; prototype chain inheritance

Core: use the instance of the parent class as the prototype of the subclass

Function Cat () {} Cat.prototype = new Animal (); Cat.prototype.name = 'cat';// Test Codevar cat = new Cat (); console.log (cat.name); console.log (cat.eat (' fish')); console.log (cat.sleep ()); console.log (cat instanceof Animal); / / true console.log (cat instanceof Cat); / / true

Features:

A very pure inheritance relationship. An instance is an instance of a subclass and an instance of a parent class.

The parent class adds prototype methods / prototype properties, which can be accessed by all subclasses.

Simple and easy to implement

Disadvantages:

To add properties and methods to a subclass, add instance properties to the Cat instance in the Cat constructor. If you want to add prototype properties and methods, you must execute them after statements such as new Animal ().

Unable to implement multiple inheritance

All properties from the prototype object are shared by all instances

When creating a subclass instance, you cannot pass parameters to the parent class constructor

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