类与类型

TypeScript Class

interface Printable {
  print(): string;
}

class Animal implements Printable {
  // 参数属性简写
  constructor(
    public name: string,
    private _age: number,
    protected type: string = 'unknown'
  ) {}

  get age(): number { return this._age; }

  print(): string {
    return `${this.name} (${this.type})`;
  }
}

abstract class Shape {
  abstract area(): number;
  describe() { return `Area: ${this.area()}`; }
}