c - 我需要一个可以禁止字符输入的函数，我只需要用户输入整数

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

阅读doc on scanf ，然后更改代码以检查调用 scanf 的返回值。 is digital(amount) 仅当用户输入与当前代码页中的字符匹配的值时才能成功，因此请停止调用它。