构造函数原型循环参考JavaScript [英] Constructor-Prototype cyclic reference JavaScript

问题描述

我正在使用函数对象的构造函数的属性撰写博客，并碰到了这一行：

函数对象的prototype属性将构造函数属性设置为函数本身

含义是以下函数对象

 函数Student（name，age）{
 this.name = name; 
 this.age =年龄； 
} 
  

将具有以下原型

{构造函数：学生}

 函数Student （）{} console.log（Student.prototype）; console.log（Student.prototype.constructor）; console.log（Student.prototype.constructor.prototype）; console.log（Student.prototype.constructor.prototype.constructor）; console.log（Student.prototype.constructor.prototype.constructor.prototype）;  

表示原型具有构造函数属性，该属性设置为具有相同原型对象的函数本身。是因为某些原因还是仅仅是语言功能。我找不到在此处进行循环引用的任何理由。

任何帮助表示感谢。谢谢。

解决方案

是的，这只是一种语言功能。还有一个非常有用的东西：

• 使用构造函数上的 .prototype 引用在使用 new


• .constructor 原型上的引用可用于从实例访问类，例如创建克隆，重新初始化实例，访问类名，或仅用于检查值。



I was working a blog on constructor property of a function object and came across this line:

The prototype property of a function Object has the constructor property set to the function itself

Meaning, the following function object

function Student(name,age) {
    this.name = name;
    this.age = age;
}

will have the following prototype

{constructor : Student}

    function Student() {
    }

    console.log(Student.prototype);
    console.log(Student.prototype.constructor);
    console.log(Student.prototype.constructor.prototype);
    console.log(Student.prototype.constructor.prototype.constructor);
    console.log(Student.prototype.constructor.prototype.constructor.prototype);

which means the prototype has the constructor property which is set to the function itself that has the same prototype object. Does this have some reasons or it was just a language feature. I couldn't find any reason for having circular reference here.

Any help appreciated. Thanks.

解决方案

Yes, this is just a language feature. And a pretty useful one:

• the .prototype reference on the constructor is used to set up inheritance when creating a new instance with new
• the .constructor reference on the prototype can be used to access the "class" from the instance, e.g. to create a clone, to re-initialise the instance, to access the class name, or just for checking the value.

这篇关于构造函数原型循环参考JavaScript的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！