Integer error C

Question

This is what I have now:

int main() {
int number;
printf("Type your number: ");
scanf("%i",&number);

char code[4];
printf("Type your code: ");
scanf("%s",&code);

When I type anything but numbers in the first one the script goes all crazy, it just shows

Type your number: NOTaNUMBER

Type your code: THErestOFtheSCRIPT

-- Back to command line

What I want it to do is

Type your number: NOTaNUMBER

You didn't enter a number

-- Back to command line

How can I do this?

This is different from the said duplicate. I'm talking about C here, not C++. C doesn't know cin, the answer to the said duplicate. However, an answer was found below

http://stackoverflow.com/questions/4072190/check-if-input-is-integer-type-in-c — marsh, Mar 16 '15 at 20:21
Okay, this is just no duplicate of that: C++ works totally different in this case... — InzeBielderman, Mar 16 '15 at 20:33

score 1 · Accepted Answer · answered Mar 16 '15 at 20:22

1

For input string use

  scanf("%s",code);

or better

  scanf("%3s",code);

To check correct input for number use value returned by scanf:

   char ch;
   if( 1 == scanf("%i",&number) )
   {
        // use correct number
   }
   else
   {
        // clean input bufer
       while( (ch = getchar()) != '\n' && ch != EOF);
   }

answered Mar 16 '15 at 20:22

petrovich

251
1
6

1

Your code breaks if `getchar()` returns `EOF` it will go into infinite loop. – Iharob Al Asimi Mar 16 '15 at 20:23
ok. I added checking for EOF. thanks for suggestion – petrovich Mar 16 '15 at 20:27

Integer error C

1 Answers1