在 Java 中打开枚举 [英] Switch on Enum in Java

问题描述

为什么不能在 Java 中打开枚举?这看起来很简单，并且可以编写一些方便的代码.这个问题也适用于 String 的.您可以打开 char，但不能打开 String ...?

Why can't you switch on an enum in Java? It seems simple enough to do and would make for some convenient code. Also this question could apply to String's. You can switch on a char, but not a String ...?

推荐答案

你绝对可以打开枚举.从 Java 教程 发布的示例.

You definitely can switch on enums. An example posted from the Java tutorials.

public enum Day {
    SUNDAY, MONDAY, TUESDAY, WEDNESDAY, 
    THURSDAY, FRIDAY, SATURDAY 
}

public class EnumTest {
    Day day;

    public EnumTest(Day day) {
        this.day = day;
    }

    public void tellItLikeItIs() {

        switch (day) {
            case MONDAY: 
                System.out.println("Mondays are bad.");
                break;

            case FRIDAY: 
                System.out.println("Fridays are better.");
                break;

            case SATURDAY:
            case SUNDAY: 
                System.out.println("Weekends are best.");
                break;

            default:
                System.out.println("Midweek days are so-so.");
                break;
        }
    }
}

这篇关于在 Java 中打开枚举的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！