The new keyword in JavaScript is detailed

As in other high-level languages JavaScript also has the new operator, and we know that the new operator is used to instantiate a class to allocate an instance object in memory. But in JavaScript, all things are objects, why do we create objects through new? This article will bring you together to explore the mysteries of new in JavaScript ...

First, recognize the new operator:

function Animal(name){
        this.name = name;
    }
    Animal.color = "black";
    Animal.prototype.say = function(){
        console.log("I‘m " + this.name);
    };
    var cat = new Animal("cat");

    console.log(
       cat.name,  //cat
       cat.height //undefined
    );
    cat.say(); //I‘m cat

    console.log(
       Animal.name, //Animal
       Animal.color //back
    );
    Animal.say(); //Animal.say is not a function

Constructor prototype Object object instance (2018-09-09--Baidu map gives inspiration)

Source: https://www.cnblogs.com/AaronNotes/p/6529492.html

The new keyword in JavaScript is detailed