Undesired Output - Printing out Two Numbers

Question

I'm fairly new to C programming, so I figured I'd try writing a simple program to print two int numbers. I prompt the user for both numbers, and then just print both using printf

However, upon running the program, I get a result which is really bizarre.

For instance...

Enter first int: 5
Enter second int: 3
First int: 2130567168
Second int: 2686756

My code is below...

#include <stdio.h>

int main()
{
    int x, y;

    printf("Enter first number: ");
    scanf("%i", x);

    printf("Enter second number: ");
    scanf("%i", y);

    printf("%i\n%i%\n",x,y);

    return 0;
}

Change `scanf("%i", x);` to `scanf("%i", &x);`. Do same for second scan. — haccks, Feb 20 '15 at 06:10
possible duplicate of [c scanf question](http://stackoverflow.com/questions/2062648/c-scanf-question) — Axalo, Feb 20 '15 at 06:21

Rizier123 · Answer 1 · 2015-02-20T06:15:15.933

5

This is because you forgot the & in the scanf statement. So change it to this:

scanf("%i", &y);
scanf("%i", &x);
          //^ See here

Also you have one % too much in your printf statement. Because % is for format specifiers, so if you want to print the symbol % you have to write it 2 times:

printf("%i\n%i%\n",x,y);
            //^ Is a format specifier so if you want to print the symbol, write it 2 times

Side note:

If you use the specifier %i in your scanf statement and you enter something like this: 035 the output would become 29, because it would be interpreted as octal number. So if you don't want that you can change the specifier to %d and 035 becomes 35

edited Feb 20 '15 at 06:15

answered Feb 20 '15 at 06:09

Rizier123

58,877
16
101
156

What would adding the `&` do? – Delfino Feb 20 '15 at 06:11
@Delfini So that you actually scan it into the address of the variable – Rizier123 Feb 20 '15 at 06:13
Ah, I see. So having `x` there just means that it's adding whatever number I input to the data already at `x`? – Delfino Feb 20 '15 at 06:14
@Delfini So that you are able to store the number of your input you have to give the address of your variable to scanf – Rizier123 Feb 20 '15 at 06:17

score 2 · Answer 2 · answered Feb 20 '15 at 06:14

Change the code like this.

scanf("%i", &y);
scanf("%i", &x);

While storing the value to the variable you have to give the address of that variable. If you are using the arrays you don't need to give that. In printf statement , use the needed specifiers.

printf("%i\n%i\n",x,y);

score 2 · Answer 3 · answered Feb 20 '15 at 07:13

2

You forgot the '&' in the scanf statement:

scanf("%i", &y);
scanf("%i", &x);
      //^ this

answered Feb 20 '15 at 07:13

user3870357

31
8

Undesired Output - Printing out Two Numbers

3 Answers3