Javascript 如何创建返回不带`new`关键字的实例的类

发布于03月04日

我想创建一个工作方式类似于BigInt的类.所以我可以做:

BigInt('111') BigInt('222').toString()个

请指导我如何编码.我正在使用NodeJS和普通的Java脚本.提前谢谢你了.

推荐答案

有几种解决方案.

可能最简单的方法是先创建一个普通类，然后再创建一个帮助器函数来创建对象.

class MyRealClass {
  constructor(name) {
    this.name = name;
  }
  hello() {
    console.log('Hello', this.name);
  }
}

function creteMyRealClass(name) {
  if (new.target) throw Error("Object should not be called with 'new'");
  return new MyRealClass(name);
}


creteMyRealClass('Alpha').hello();

另一种 Select 是使用调用Object.Create的帮助器函数

// By declaring an external object with attributes
// common to all objects of this type, you save memory
// and execution time
const MyPrototype = {
  hello() {
    console.log('Hello', this.name);
  },
};

function createMyPrototype(name) {
  if (new.target) throw Error("Object should not be called with 'new'");
  const obj = Object.create(MyPrototype);
  obj.name = name;
  return obj;
}

const b = createMyPrototype('Beta');
b.hello();