我需要一個功能，我可以禁止字符輸入，我只需要用戶的整數輸入

Question

case 'f': 
      printf ("Great!!! lets create your fixed account\n"); 

     printf ("\nA minimum purchase of 1000 units is required for this 

account\n"); 
      printf ("\nPrice per unit as of Sep. 15 is $52.69\n") 
; 
      printf ("\nPlease enter required amount of units\n"); 

      scanf("%d",&amount); 


      if (isdigit(amount)) 

       { 
       printf ("invalid input\n"); 
       success = 'f'; 
       break; 

Answer 1

閱讀doc on scanf，然後更改您的代碼以檢查您的調用scanf的返回值。如果用戶輸入的值與當前代碼頁中的字符匹配，則數字（金額）只能成功，因此請停止調用它。