为什么原型函数没有使用正确的版本？

Question

我正在尝试了解 JS prototype 继承机制，例如 es6 uses. When I execute the below code in the browser(chrome ironman.villain(); 函数无法从中读取 name 属性这个。我希望 this 成为 MarvelHero 对象，但它实际上是对 window 的引用。 ironman.summarize() 也因类似原因而失败。这是为什么？

ironman.introduce(); 和 ironman.friends(); 正确读取 this.name 变量并打印它。

var heroes = [];

// Hero constructor
function Hero (name, universe) {
  this.name = name;
  this.universe = universe;
  this.introduce = () => {
    return `I am ${this.name} and I belong to the ${this.universe} universe.`;
  }
  heroes.push(this);
}

// MarvelHero constructor
function MarvelHero (name) {
  this.universe = 'Marvel Comics';
  Hero.call(this, name, this.universe);
  this.friends = () => {
    return `${this.name} has friends: ${heroes.filter(hero => hero instanceof MarvelHero && hero.name !== this.name).map(hero => hero.name).join(', ')}.`;
  };
}

// DCHero constructor
function DCHero (name) {
  this.universe = 'DC Comics';
  Hero.call(this, name, this.universe);
  this.friends = () => {
    return `${this.name} has friends: ${heroes.filter(hero => hero instanceof DCHero && hero.name !== this.name).map(hero => hero.name).join(', ')}.`;
  };
}

// Parent prototype
Hero.prototype.summarize = () => {
  return `${this.name} => ${this.universe}`;
}

// Inherit from Hero's prototype
MarvelHero.prototype = Object.create(Hero.prototype);
DCHero.prototype = Object.create(Hero.prototype);

// Assign constructor prototypes to self
MarvelHero.prototype.constructor = MarvelHero;
DCHero.prototype.constructor = DCHero;

// MarvelHero prototype
MarvelHero.prototype.villain = () => {
  return `${this.name} has Loki`;
}

// DCHero prototype
DCHero.prototype.villain = () => {
  return `${this.name} has The Joker`;
}

let ironman = new MarvelHero('Ironman');
let captain = new MarvelHero('Captain America');
let spiderman = new MarvelHero('Spiderman');
let hulk = new MarvelHero('The Hulk');
let thor = new MarvelHero('Thor');
let doctor = new MarvelHero('Doctor Strange');
let panther = new MarvelHero('Black Panther');

let batman = new DCHero('Batman');
let superman = new DCHero('Superman');
let wonder = new DCHero('Wonder Woman');
let aquaman = new DCHero('Aquaman');

ironman.introduce();
ironman.friends();
ironman.villain();
ironman.summarize();

batman.introduce();
batman.friends();
batman.villain();
batman.summarize();

Answer 1

您的函数是在全局范围内定义的，因此 this 引用 window 对象。

为了让 this 引用父对象，您需要它们成为对象的一部分

{
     DChero : function(name){}
}

或者将您的代码括在括号中并将其用作 iife

为什么原型函数没有使用正确的版本？

Why is the prototype function not using the correct version of this?

javascript

ecmascript-6

prototype

prototypal-inheritance