【愚公系列】《鸿蒙原生应用开发从零基础到多实战》006-TypeScript 中的元组

// 数组
const numArr: number[] = [1, 2, 3];
const mixedArr: (string | number)[] = ['a', 1]; 

// 元组
let userInfo: [number, string, boolean] = [1, 'admin', true];

// 正确定义
let point: [number, number] = [10, 20]; 

// 类型顺序错误
point = ['x', 30]; // ❌ Type 'string' is not assignable to 'number'

// 越界赋值（联合类型生效）
point.push(30); // ✅ 合法，但无法通过索引访问point[2]

const response: [number, string] = [200, 'OK'];
const [statusCode, message] = response;
console.log(`状态码: ${statusCode}, 消息: ${message}`);

// 数值型枚举（默认从0开始）
enum Direction { Up, Down, Left, Right }

// 字符串枚举
enum LogLevel { 
  Info = 'INFO',
  Error = 'ERROR'
}

// 混合枚举（不推荐）
enum Status { 
  Success = 200,
  Fail = 'FAIL'
}

// 显式赋值示例
enum Gear {
  First = 1,    // 显式设置为1
  Second = 3,   // 跳跃赋值
  Third = 5
}

console.log(Gear.Second); // 输出: 3

// 驾驶行为接口
interface Drivable {
  start(): void;
  drive(time: number, speed: Gear): void;
  getKilometer(): number;
}

// 抽象类实现接口
abstract class Car implements Drivable {
  protected _isRunning: boolean = false;
  protected _distance: number = 0;

  public start(): void {
    this._isRunning = true;
  }

  public abstract drive(time: number, speed: Gear): void;

  public getKilometer(): number {
    return this._distance;
  }
}

// BMW子类（泛型应用）
class BMW<T extends Color> extends Car {
  private color: T;

  constructor(colorType: T) {
    super();
    this.color = colorType;
  }

  public drive(time: number, speed: Gear): void {
    if (this._isRunning) {
      this._distance += time * speed;
    }
  }

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

// 实例创建与操作
const myBMW = new BMW(Color.Red);
myBMW.start();
myBMW.drive(2, Gear.First);   // 2小时 × 1档速度
myBMW.drive(1.5, Gear.Third); // 1.5小时 × 5档速度

// DOM输出
document.body.innerHTML = `
  总里程: ${myBMW.getKilometer()}km 
  颜色: ${myBMW.getColor()}
`;

const config: readonly [string, number] = ['localhost', 8080];

enum Gear { First = 1 }
console.log(Gear[1]); // 输出: "First"