如何使用ES5扩展ES6类? [英] How do I extend an ES6 class with ES5?

问题描述

执行此操作的原因很复杂，但是归结为无法理解mixin或其他任何修改ES6类原型的方法.所以我回到了ES5，但是我不知道如何在没有 new 的情况下调用ES6类的构造函数:

The reasons for doing this are complicated, but it boils down to flow not understanding mixins or any other way of modifying an ES6 class's prototype. So I'm falling back to ES5, but I can't figure out how to call the constructor of an ES6 class without new:

class A {
  constructor() {}
}

function B() {
  // what do I put here?  I would do something like
  // A.prototype.constructor.call(this) but that throws an error saying the
  // constructor can only be called with `new`
}
B.prototype = Object.create(A.prototype);

推荐答案

亲自回答:

class A {
  constructor() {}
}

function B() {
  Object.assign(this, new A());
}
B.prototype = Object.create(A.prototype);

不确定这里是否有副作用

Not sure if there are any side-effects here or not

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