C-切换多个案例编号 [英] C - Switch with multiple case numbers

问题描述

因此，我的教授要求我们创建一个转换语句.我们只允许使用"SWITCH" 语句来执行该程序.他希望我们输入一个数字，然后显示它(如果它在数字范围内)，并将显示哪个公文包数字，如下所示.现在...我知道，对于这种类型的程序，使用 IF语句更容易.进行案例1:案例2:案例3 ...案例30可以使用，但由于数量范围，将花费太多时间.

So my professor asked us to create a switch statement. We are allowed to use only the "SWITCH" statement to do the program. He wants us to input a number and then display it if it is on the number range and what briefcase number will be taken as shown below. Now... I know that for this type of program it is easier to use the IF statement. Doing Case 1: Case 2: Case 3...Case 30 will work but will take too much time due to the number range.

#include <stdio.h>
main()
{
      int x;
      char ch1;
      printf("Enter a number: ");
      scanf("%d",&x);
      switch(x)
      {
                 case 1://for the first case #1-30
                 case 30:
                      printf("The number you entered is >= 1 and <= 30");
                      printf("\nTake Briefcase Number 1");
                      break;         
                 case 31://for the second case #31-59
                 case 59:
                      printf("The number you entered is >= 31 and <= 59");
                      printf("\nTake Briefcase Number 2");
                      break;                 
                 case 60://for the third case #60-89
                 case 89:
                      printf("The number you entered is >= 60 and <= 89");
                      printf("\nTake Briefcase Number 3");
                      break;                 
                 case 90://for the fourth case #90-100
                 case 100:
                      printf("The number you entered is >= 90 and <= 100");
                      printf("\nTake Briefcase Number 4");
                      break;      
                 default:
                     printf("Not in the number range");
                     break;

                 }
      getch();
      }

我的教授告诉我们，这样做的方法更短，但是不会告诉我们如何做.我想缩短它的唯一方法是使用IF，但我们不允许这样做.关于如何解决这个问题有什么想法吗?

My professor told us that there is a shorter way on how to do this but won't tell us how. The only way I can think of shortening it is by using IF but we are not allowed to. Any Ideas on how I can make this work out?

推荐答案

借助GCC和CLang，您可以使用大小写范围，如下所示:

With GCC and CLang, you can use case ranges, like this:

switch (x){

case 1 ... 30:
    printf ("The number you entered is >= 1 and <= 30\n");
    break;
}

唯一的交叉编译器解决方案是使用这样的case语句:

The only cross-compiler solution is to use case statements like this:

switch (x){

case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
    printf ("The number you entered is >= 1 and <= 6\n");
    break;
}

编辑:使用某种方式达到switch (x / 10)的效果是执行此操作的另一种好方法.当范围不是10的差异时，使用GCC案例范围可能会更简单，但另一方面，您的教授可能不会接受GCC扩展名作为答案.

Using something to the effect of switch (x / 10) is another good way of doing this. It may be simpler to use GCC case ranges when the ranges aren't differences of 10, but on the other hand your professor might not take a GCC extension as an answer.

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