JavaScript的OOPS抽象 javascript抽象|JavaScript

本文概要

要记住的要点
JavaScript的抽象实例

抽象是隐藏实现细节，并只显示功能给用户的一种方式。换句话说，它忽略无关的细节，并只显示所需要的一个。
要记住的要点

我们不能创建抽象类的一个实例。
它减少了代码重复。

JavaScript的抽象实例实例1
【JavaScript的OOPS抽象】让我们来看看我们是否可以创建抽象类与否的一个实例。

< script> //Creating a constructor function function Vehicle() { this.vehicleName= vehicleName; throw new Error("You cannot create an instance of Abstract class"); } Vehicle.prototype.display=function() { return this.vehicleName; } var vehicle=new Vehicle(); < /script>

实例2
让我们看一个例子来实现抽象。

< script> //Creating a constructor function function Vehicle() { this.vehicleName="vehicleName"; throw new Error("You cannot create an instance of Abstract Class"); } Vehicle.prototype.display=function() { return "Vehicle is: "+this.vehicleName; } //Creating a constructor function function Bike(vehicleName) { this.vehicleName=vehicleName; } //Creating object without using the function constructor Bike.prototype=Object.create(Vehicle.prototype); var bike=new Bike("Honda"); document.writeln(bike.display()); < /script>

输出：

Vehicle is: Honda

实例3
在这个例子中，我们使用instanceof操作符测试对象是否指的是对应的类。

< script> //Creating a constructor function function Vehicle() { this.vehicleName=vehicleName; throw new Error("You cannot create an instance of Abstract class"); } //Creating a constructor function function Bike(vehicleName) { this.vehicleName=vehicleName; } Bike.prototype=Object.create(Vehicle.prototype); var bike=new Bike("Honda"); document.writeln(bike instanceof Vehicle); document.writeln(bike instanceof Bike); < /script>

输出：