oh my gosh i can't even get isdigit to work

[Cloudboy]

I have tried the most basic of programs and I just cannot get it!

int main(void){
    int guess;
    scanf("%d", &guess);

            if(isdigit(guess)){printf("true");}

system("pause");

    return 0;
    
}

This program displays nothing, even when I input a digit such as 5

[Peter87]

try add fflush(stdout); after the call to printf.

[Cloudboy]

int main(void){
    int guess;
    
    scanf("%d", &guess);

            if(isdigit(guess)){printf("true");  fflush(stdout);}

system("pause");

    return 0;
    
}

Doesn't work. After I input 5 it just says press any key to quit. I'm running Dev-C++ but it's not working when i compile it under cygwin either.

[Peter87]

Oh, now I see. If you input 50 it will print "true" ;)

The problem is that you read in an int value but isdigit works on char values.

[Cloudboy]

ok thanks! I changed it to this and it works now:

int main(void){
    char guess;
    
    scanf("%c", &guess);

            if(isdigit(guess)){printf("true");}

system("pause");

    return 0;
    
}

I thought I was going crazy there for a while lol