在switch语句中，为什么所有的情况都被执行？ [英] In a switch statement, why are all the cases being executed?

问题描述

我的代码带有开关语句，我从这里得到了发布，它绝对正常：

I have this code with the switch statement which I got from this post, and it works absolutely fine:

String getOrdinal(final int day) {
    if (day >= 11 && day <= 13) {
        return "th";
    }
    switch (day % 10) {
        case 1: return "st";
        case 2: return "nd";
        case 3: return "rd";
        default: return "th";
    }
}

但如果我将其更改为如下所示，它会中断，因为 case 1 之外的所有情况都会被执行：

But if I change it to something like the following, it breaks, as all the cases besides case 1 gets executed:

  static String getOrdinal(final int day) {
    StringBuilder ordinalBuilder = new StringBuilder();
    ordinalBuilder.append("<sup>");
    if (day >= 11 && day <= 13) {
        ordinalBuilder.append("th") ;
    }
    switch (day % 10) {
        case 1: ordinalBuilder.append("st");
        case 2: ordinalBuilder.append("nd");
        case 3: ordinalBuilder.append("rd");
        default: ordinalBuilder.append("th");
    }
    ordinalBuilder.append("</sup>");
   return ordinalBuilder.toString();
 }

打印 2< sup> ndrdth< / sup> ; 当我传入 2 时。我尝试将构建器更改为缓冲区，但我得到了相同的响应......这可能是一个错误还是我犯了一些错误？

This prints 2<sup>ndrdth</sup> when I pass in 2. I tried changing the builder to buffer but I got the same response... Could this be a bug or am I making some mistake?

推荐答案

这是您代码中的错误。在每个案例之后，您忘了输入中断：

It's a bug in your code. You forgot to put in a break after each case:

switch (day % 10) {
    case 1: ordinalBuilder.append("st"); break;
    case 2: ordinalBuilder.append("nd"); break;
    case 3: ordinalBuilder.append("rd"); break;
    default: ordinalBuilder.append("th"); break;
}

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