#instanceof

function myInstanceof(obj, constructor) {
  // 1. 排除基本类型和非对象
  if (typeof obj !== 'object' || obj === null) return false;

  // 2. 获取对象的原型
  let proto = Object.getPrototypeOf(obj);

  // 3. 遍历原型链，对比 constructor.prototype
  while (proto !== null) {
    if (proto === constructor.prototype) {
      return true;
    }
    proto = Object.getPrototypeOf(proto);
  }

  return false;
}

const n = new Number(1)
console.log(myInstanceof(n, Number))