Javascript ECMAScript2015类vs Object.create vs new vs Object.setPrototypeOf

随着ES6的出现，我们获得了一种创建对象的新方法。我的问题是我们现在应该如何创建对象？ 假设新的操作员是这样工作的

function createNewObject(parentFunction){
    var obj = {};
    Object.setPrototypeOf(obj, parentFunction.prototype);
    return parentFunction.apply(obj, Array.prototype.slice.call(arguments,1)) || obj;
}

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但当类被创建时，到底发生了什么呢？当前在es6中创建对象的“正确”方式是什么？

使用es6，我们将使用以下语法创建一个类：

class Animal{
    constructor(name){
        this.name = name;
    } 
    saySomething(){
        console.log('Hi, my name is' + this.name);
    }
}

如果我们想创建一个名为

Cat

的子类，它将如下所示：

class Cat extends Animal {
    constructor(name){
        super(name);
    }   
    saySomething(){
        console.log('Meow, my name is ' + this.name);
    }
}

var Animal = function(name){
    this.name = name;
}
Animal.prototype.saySomething = function(){
   console.log('hi, my name is ' + this.name);
}

var Cat = function(name){
    Animal.call(this, name);
}
Cat.prototype = Object.create(Animal.prototype);
Cat.prototype.saySomething = function(){
  console.log('Meow, my name is ' + this.name);
}

如果要创建类型为

Cat

的对象，我们将执行以下操作：

let cat1 = new Cat('Felix');
cat1.saySomething(); //Outputs 'meow, my name is Felix'

es6类的特性是语法上的糖分，而不是原型方法。如果我们使用常规原型方法创建

Animal

类，它将如下所示：

class Cat extends Animal {
    constructor(name){
        super(name);
    }   
    saySomething(){
        console.log('Meow, my name is ' + this.name);
    }
}

var Animal = function(name){
    this.name = name;
}
Animal.prototype.saySomething = function(){
   console.log('hi, my name is ' + this.name);
}

var Cat = function(name){
    Animal.call(this, name);
}
Cat.prototype = Object.create(Animal.prototype);
Cat.prototype.saySomething = function(){
  console.log('Meow, my name is ' + this.name);
}

子类将如下所示：

class Cat extends Animal {
    constructor(name){
        super(name);
    }   
    saySomething(){
        console.log('Meow, my name is ' + this.name);
    }
}

var Animal = function(name){
    this.name = name;
}
Animal.prototype.saySomething = function(){
   console.log('hi, my name is ' + this.name);
}

var Cat = function(name){
    Animal.call(this, name);
}
Cat.prototype = Object.create(Animal.prototype);
Cat.prototype.saySomething = function(){
  console.log('Meow, my name is ' + this.name);
}

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这个问题还讨论了Object.create和Object.setPrototypeOf之间的区别。但答案甚至没有提到Object.setPrototypeOf。无法理解如何选择答案。引用自Object。setPrototypeOf（）方法将指定对象的原型（即内部[[prototype]]属性）设置为另一个对象或null。“