car.ts

abstract class Car {

  protected buildId: string;

  /**
   * 製造番号
   */
  public getBuildId(): string {
    return this.buildId;
  }

  abstract drive(): void;
}

class SuperCar extends Car {

  private static buildNumber = 0;

  public static getBuildedCarsCount(): number {
    return this.buildNumber;
  }


  constructor(private color: string = 'red') {
    super();
    this.buildId = `supercar-${++SuperCar.buildNumber}`;
  }

  public getColor(): string {
    return this.color;
  }

  public drive(): void {
    console.log('super car drives!');
  }
}

class HyperCar extends Car {

  private static buildNumber = 0;

  public static getBuildedCarsCount(): number {
    return this.buildNumber;
  }

  constructor(private color: string = 'black') {
    super();
    this.buildId = `HYPER_CAR_${++HyperCar.buildNumber}`;
  }

  public getColor(): string {
    return this.color;
  }

  public drive(): void {
    console.log('SUPER CAR DRIVES!');
  }
}

const superCarA = new SuperCar();

console.log(superCarA.getColor());
// red
console.log(superCarA.getBuildId());
// supercar-1

const superCarB = new SuperCar('blue');
console.log(superCarB.getColor());
// blue
console.log(superCarB.getBuildId());
// supercar-2

console.log('SuperCarは', SuperCar.getBuildedCarsCount(), '台製造されています。');
// SuperCarは 2 台製造されています。


const hyperCarC = new HyperCar();

console.log(hyperCarC.getColor());
// black
console.log(hyperCarC.getBuildId());
// HYPER_CAR_1

const hyperCarD = new HyperCar('silver');
console.log(hyperCarD.getColor());
// silver
console.log(hyperCarD.getBuildId());
// HYPER_CAR_2

console.log('HyperCarは', HyperCar.getBuildedCarsCount(), '台製造されています。');
// HyperCarは 2 台製造されています。