Factory、Switch和Random - java

interface Animal {
    void speak();
}

class Dog implements Animal {
    @Override
    public void speak() {
        System.out.println("Woof!");
    }
}

class Cat implements Animal {
    @Override
    public void speak() {
        System.out.println("Meow!");
    }
}

class AnimalFactory {
    public static Animal createAnimal(String type) {
        if ("Dog".equalsIgnoreCase(type)) {
            return new Dog();
        } else if ("Cat".equalsIgnoreCase(type)) {
            return new Cat();
        }
        return null;
    }
}

public class Main {
    public static void main(String[] args) {
        Animal dog = AnimalFactory.createAnimal("Dog");
        dog.speak(); // 输出: Woof!

        Animal cat = AnimalFactory.createAnimal("Cat");
        cat.speak(); // 输出: Meow!
    }
}

public class Main {
    public static void main(String[] args) {
        String day = "Monday";

        switch (day) {
            case "Monday":
                System.out.println("今天是星期一");
                break;
            case "Tuesday":
                System.out.println("今天是星期二");
                break;
            case "Wednesday":
                System.out.println("今天是星期三");
                break;
            default:
                System.out.println("未知星期");
                break;
        }
    }
}

import java.util.Random;

public class Main {
    public static void main(String[] args) {
        Random random = new Random();

        int randomNumber = random.nextInt(100); // 生成一个0到99之间的随机整数
        System.out.println("随机整数: " + randomNumber);

        double randomDouble = random.nextDouble(); // 生成一个0.0到1.0之间的随机双精度浮点数
        System.out.println("随机双精度浮点数: " + randomDouble);
    }
}