#include<stdio.h>

char b[9];
void writeinfo()
{   
    printf("Enter stock name:");
    scanf("%s",b);
    printf("How much did you pay for it?");
    scanf("%s",b);
    puts("stock added\n");
}

int main()
{
    int is_Quit = 1;
    char a;
    while(is_Quit)
    {
        puts("Stock Portfolio Thing\n");
        puts("A - Add newstock");
        puts("L - List stocks");
        puts("R - Replace stocka");
        puts("Q - Quit\n");
        printf("Your choice:");
        scanf("%c",&a);

        switch(a)
        {
            case 'A' :
            case 'a' :
                puts("Add newstock\n");
                writeinfo();
                break;
            case 'L' :
            case 'l' :
                puts("List stocks\n");
                break;
            case 'R' :
            case 'r' :
                puts("Replace stocka\n");
                break;
            case 'Q' :     
            case 'q' :
                puts("Quit\n");
                is_Quit = 0;
                break;
            default :
                puts("Error\n");
                break;
        }
    }
   
    getch(); return(0);
}

为什么因老是进入default而无法循环呢？？？纠结啊。。。

谢谢啊，大侠！！