// simulate Implement of operator new
function OperatorNew(constructor, ...args) {
  // 1. create a new null object
  const obj = {};
  // 2. set prototype for the new object
  Object.setPrototypeOf(obj, constructor.prototype);
  // 3. points the this of the constructor to the new object
  const result = constructor.apply(obj, args);
  // 4. return by result
  return result instanceof Object ? result : obj;
}
function Person(name, age) {
  this.name = name;
  this.age = age;
}
Person.prototype.say = function () {
  console.log(this.name, this.age);
};
function test() {
  const instance = OperatorNew(Person, 'leon', 20);
  console.log(instance);
  instance.say();
}
test();