如何在typescript中实现工厂方法？

// Step 1: 定义抽象基类或接口
abstract class Product {
  abstract operation(): void;
}

// Step 2: 创建具体的产品类
class ConcreteProductA extends Product {
  operation(): void {
    console.log('ConcreteProductA operation');
  }
}

class ConcreteProductB extends Product {
  operation(): void {
    console.log('ConcreteProductB operation');
  }
}

// Step 3: 创建工厂类
class Factory {
  static createProduct(type: string): Product {
    switch (type) {
      case 'A':
        return new ConcreteProductA();
      case 'B':
        return new ConcreteProductB();
      default:
        throw new Error('Invalid product type.');
    }
  }
}

// 示例用法
const productA = Factory.createProduct('A');
productA.operation(); // 输出: ConcreteProductA operation

const productB = Factory.createProduct('B');
productB.operation(); // 输出: ConcreteProductB operation