Typescript如何向对象构造函数添加属性？

class Person {
  name: string;
  age: number;

  constructor(name: string, age: number) {
    this.name = name;
    this.age = age;
  }
}

const person = new Person("John", 25);
console.log(person.name); // 输出：John
console.log(person.age); // 输出：25

class Person {
  constructor(public name: string, public age: number) {}
}

const person = new Person("John", 25);
console.log(person.name); // 输出：John
console.log(person.age); // 输出：25

function addProperty(target: any) {
  target.prototype.city = "New York";
}

@addProperty
class Person {}

const person = new Person();
console.log(person.city); // 输出：New York