while循环代码不起作用(keepgoing ='y')

所以我正在学习如何在C语言中使用while和for循环，但是这段代码似乎无法正常工作. scanf语句似乎被忽略了，循环只是重复自身而无需我输入'Y'使其重复.这是代码:

So I'm learning how to use the while and for loops in C but this code won't seem to work. the scanf statement seems to be getting ignored and the loop just repeats itself without requiring me to input 'Y' for it to repeat. Here's the code:

void showCommission();

void main() {
    char keepGoing='y';
    while(keepGoing=='y') {
        showCommission();
        printf("Do you want to calculate another?\n");
        scanf("%c",&keepGoing);
   }
}

void showCommission() {
    float sales,commission;
    const float COM_RATE=0.10;
    printf("Enter the amount of sales\n");
    scanf("%f",&sales);
    commission=sales*COM_RATE;
    printf("The commission is $%f.\n",commission);
}

这是运行代码给我的:

Enter the amount of sales                                                                         
5000                                                                                              
The commission is $500.000000.                                                                    
Do you want to calclulate another?    

...Program finished with exit code 10                                                             
Press ENTER to exit console.  

它从不提示我输入y，并且代码由于某种原因而退出.

it never prompts me to enter y and the code just exits for some reason.