How to use constructor in js

In JavaScript <code>constructor</code> Usage

<code>constructor</code> is a built-in property in JavaScript that points to the function that creates the object. It is used to initialize the state of an object when it is created.

Syntax:

<code>constructor</code>

Usage:

<code>constructor</code> Can be used for the following purposes:

1. Get the function that creates the object:

<code class="js">let obj = new Object();
console.log(obj.constructor); // 输出：Object</code>

2. Create a new object:

<code>constructor</code> Can be used as a function to create new objects:

<code class="js">class Person {
  constructor(name) {
    this.name = name;
  }
}

let person = new Person("John");
console.log(person instanceof Person); // 输出：true</code>

3. Set the prototype of an object:

##constructor Can be used to set the prototype of the object:

<code class="js">function Animal() {}

function Dog() {}
Dog.prototype = new Animal();

let dog = new Dog();
console.log(dog.constructor); // 输出：Dog</code>

Note:

• constructor is a read-only property and cannot be Revise.
For objects that do not have an explicitly defined constructor (such as objects created through object literals), their
• constructor properties point to the Object function.
The concept of class was introduced in ES6. A class usually defines a
• constructor method, which is used to initialize instances of the class.

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