如何在angular 2中设置具有新属性的类

export class Person {
  name: string;
  age: number;
}

import { Component } from '@angular/core';
import { Person } from './person';

@Component({
  selector: 'app-root',
  template: `
    <h1>{{ person.name }}</h1>
    <p>Age: {{ person.age }}</p>
  `
})
export class AppComponent {
  person: Person;

  constructor() {
    this.person = new Person();
    this.person.name = 'John';
    this.person.age = 25;
  }
}