c - 带有嵌套开关的 while 循环没有输出

Question

#include <stdio.h>
int main()
{
char cha;
int m=0;
int f=0;
int tot;
while(cha=='m'||cha=='M'||cha=='F'||cha=='f')
{   
    printf("What is your gender?(m or f):\n");      
    scanf(" %c",&cha);
    switch (cha)
    {
        case 'm':
        case 'M':
        printf("\nYou are a male");
        ++m;
        printf("\nPress a to total up");
        break;

        case 'f':
        case 'F':   
        printf("\nYou are a female");
        ++f;
        printf("\nPress a to total up");
        break;

        case 'a':
        tot=m+f;
        printf("\nThe number of male is %d and the number of female is %d",m,f);
        printf("\nThe total of male and female is:%d",tot);
        break;
    }

}

return 0;

}

所以我只是乱搞我的代码，试图建立一个程序，可以总结程序中输入的 m 和 f 的数量，最终根本没有输出。程序刚刚终止，没有显示任何输出。我尝试在 while 表达式末尾添加分号，但 while 循环最终甚至无法运行。我的代码有什么问题吗？

Answer 1

你没有给 cha 一个值。所以它不会进入 while 。我认为这个版本更好。而且错误处理也非常重要。

#include <stdio.h>
int main()
{

char cha;
int m=0;
int f=0;
int tot;
bool end = false;
while(end==false)
{   
    printf("What is your gender?(m or f):\n");      
    scanf(" %c",&cha);

    switch (cha)
    {
        case 'm':
        case 'M':
        printf("\nYou are a male");
        ++m;
        printf("\nPress a to total up");
        break;

        case 'f':
        case 'F':   
        printf("\nYou are a female");
        ++f;
        printf("\nPress a to total up");
        break;

        case 'a':
        tot=m+f;
        end = true;
        printf("\nThe number of male is %d and the number of female is %d",m,f);
        printf("\nThe total of male and female is:%d",tot);
        break;

        default:
        printf("\nEnter valid sex.");
    }

}

return 0;