枚举

枚举的优势
类型安全,紧凑有效的数据定义,可以和程序其他部分完美交互,运行效率高
1.定义枚举类,使用enum 关键字

package test.meiju;

public enum Seasons2 {
    SPRING, SUMMER, AUTUMN, WINTER
}

2.定义完成后就可以使用啦

package test.meiju;

public class Demo {
    public static void doit(int i) {
        switch (i) {
        case Seasons.SPRING:
            System.out.println("春天");
            break;
        case Seasons.SUMMER:
            System.out.println("夏天");
            break;
        case Seasons.AUTUMN:
            System.out.println("秋天");
            break;
        case Seasons.WINTER:
            System.out.println("冬天");
            break;
        }
    }

    public static void doit2(Seasons2 s) {

        switch (s) {
        case SPRING:
            System.out.println("春天");
            break;
        case SUMMER:
            System.out.println("夏天");
            break;
        case AUTUMN:
            System.out.println("秋天");
            break;
        case WINTER:
            System.out.println("冬天");
            break;
        }
    }

    public static void main(String[] args) {
        doit2(Seasons2.WINTER);
        Seasons2 summer = Seasons2.SUMMER;
        Seasons2 valueOf = Seasons2.valueOf("SUMMER");
        int compareTo = valueOf.compareTo(summer);
        int ordinal = valueOf.ordinal();
        System.out.println("compareTo" + compareTo + "ordinal" + ordinal);
        System.out.println("" + valueOf);
        Seasons2[] values = Seasons2.values();
        for (Seasons2 seasons2 : values) {
            System.out.println(seasons2);
        }
        doit(3);
    }
}