JAVA编程思想第十九章练习题

原创已于 2022-08-11 20:29:41 修改 · 482 阅读

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#java

于 2022-04-23 21:16:52 首次发布

该代码示例展示了如何使用Java的枚举类型来实现交通信号灯的改变逻辑，以及创建一个菜单系统，包含开胃菜、饮料、主菜、甜点和咖啡等各类食品的枚举。程序通过循环展示交通信号灯状态的变化，并定义了食品的各个类别。

public class E01 {
    Signal color = Signal.RED;
    public void change(){
        switch (color){
            case RED: color = Signal.GREEN;
            break;
            case GREEN: color = Signal.YELLOW;
            break;
            case YELLOW:color = Signal.RED;
        }
    }

    @Override
    public String toString() {
        return "The traffic light is "+ color;
    }

    public static void main(String[] args) {
        E01 t = new E01();
        for (int i = 0; i < 7; i++) {
            System.out.println(t);
            t.change();
        }
    }
}

练习3：

package menu;

public interface Food {
    enum Appetizer implements Food{
        SALAD, SOUP, SPRING_ROLLS;
    }
    enum Beverage implements Food{
        BEER,VINE,JUICE,COLA,WATER;
    }
    enum MainCourse implements Food {
        LASAGNE, BURRITO, PAD_THAI,
        LENTILS, HUMMOUS, VINDALOO;
    }
    enum Dessert implements Food {
        TIRAMISU, GELATO, BLACK_FOREST_CAKE,
        FRUIT, CREME_CARAMEL;
    }
    enum Coffee implements Food {
        BLACK_COFFEE, DECAF_COFFEE, ESPRESSO,
        LATTE, CAPPUCCINO, TEA, HERB_TEA;
    }
}