Question

I need to ask an input from a user and he/she should have the ability to write a float number, and I need to do some calculation on the 2 numbers, but I’m having a problem after the isdigit test…even if I enter an integer its going to the continue;

This is my code:

#include <stdio.h>
#include <ctype.h>
char get_choice(void);
float calc(float number1, float number2);

int main()
{

    float userNum1;
    float userNum2;
    get_choice();

    printf("Please enter a number:\n");
    while ((scanf("%f", &userNum1)) == 1)
    {
        if (!isdigit(userNum1))
        {
            printf("Please enter a number:\n");
            continue;
        }


        printf("Please enter another number:\n");
        while ((scanf("%f", &userNum2) == 1))
        {
            if (!isdigit(userNum2))
            {
                printf("Please enter a number:/n");
                continue;
            }
            else if (userNum2 == '0')
            {
                printf("Please enter a numer higher than 0:\n");
                continue;
            }

        }

    }
    calc(userNum1, userNum2);
    return 0;
}

float calc(float number1, float number2)

{
    int answer;

    switch (get_choice())
        {
            case 'a':
                answer = number1 + number2;
                break;
            case 's':
                answer = number1 - number2;
                break;
            case 'm':
                answer = number1 * number2;
                break;
            case 'd':
                answer = number1 / number2;
                break;
        }
    return answer;
}

char get_choice(void)

{
    int choice;

    printf("Enter the operation of your choice:\n");
    printf("a. add        s. subtract\n");
    printf("m. multiply   d. divide\n");
    printf("q. quit\n");

    while ((choice = getchar()) == 1 && choice != 'q')
    {

        if (choice != 'a' || choice != 's' || choice != 'm' || choice != 'd')
        {
            printf("Enter the operation of your choice:\n");
            printf("a. add        s. subtract\n");
            printf("m. multiply   d. divide\n");
            printf("q. quit\n");
            continue;
        }


    }
    return choice;
}

Apologize for uploading the functions as well, but since I’m a newbie the problem might be there.
Cheers.

Answer 1

isDigit() only takes a character input.
The best way to check that you are getting input correctly is to use

if(scanf("%f", &userNum) != 1) {
    // Handle item not float here
}

Since scanf() will return the number of items correctly scanned.