pset1 problem set

Question

i tried to run this code,

#include <cs50.h>
#include <stdio.h>
#include <ctype.h>

int main()
{
    int iRandom = 0;
    int iResponse = 0;


    iRandom = (rand() % 10) + 1;

    printf("\nGuess a number between 1 and 10: \n");
    scanf("%d", &iResponse);

        if isdigit(iResponse)
        printf("\nProcessing.....\n");

        else 
        printf("You did not enter a digit!\n");


    {
        if(iResponse == iRandom)
        printf("\nYou guessed right\n");

        else
        printf("You guessed wrong\n");
        printf("\nThe correct guess was %d\n", iRandom);

    }
}

but the isdigit() function keeps processing it wrong even though my input was a digit;

/home/ubuntu/workspace/fooling/ $ ./guess

Guess a number between 1 and 10: 
5
You did not enter a digit!
You guessed wrong

The correct guess was 4

can you tell me what i did wrong?

Answer 1

1. You are missing a pair of parentheses around this if statement

   if isdigit(iResponse)
   

2. You are using isdigit() wrong. Its definition is

   int isdigit( int ch );

   Checks if the given character is a numeric character (0123456789). The behavior is undefined if the value of ch is not representable as unsigned char and is not equal to EOF.

   Parameters
   ch - character to classify

   Return value
   Non-zero value if the character is a numeric character, zero otherwise.

So you have to pass to it a char and it will tell you if it's a digit, not an int. The int in the definition's parameters, is because all chars can be represented as integers in C.

3. You also have some stray curly braces.