A brief introduction to the usage of new operator in js (code)

The content of this article is a brief introduction (code) about the usage of new operator in js. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

var Func=function(){};
var func=new Func ();

new has gone through four stages:
1. Create an empty object

varobj=new Object();

2. Set up the prototype chain

obj.__proto__= Func.prototype;

3. Let this in Func point to obj and execute the function body of Func.

var result =Func.call(obj);

4. Determine the return value type of Func:

If it is a value type, return obj. If it is a reference type, an object of this reference type is returned.

if (typeof(result) == "object"){
  func=result;
}else{
    func=obj;;
}

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