Why doesn't scanf read the value correctly?

Question

Can someone tell me what is going wrong here?

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#define ERROR 0
#define MAX_INPUT_LINE 80
#define print(x) {fputs(x,stdout);}
#define SUCCESS 1

int main (long argc, char *argv[])
{
   int mode;
   printf("1 for hexidecimal or 2 for binary");
   scanf("%d", mode);

   printf("\n\n\nThe value of mode is %d\n", mode);
   return 0;
}

When I enter 2 for binary, I get this:

The value of mode is 2665564

Obviously I should get 2, what am I doing wrong?? Is it my compiler, is it bevcause I am using Cygwin? Why is mode not 2??

Answer 1

your scanf is wrong. should be:

scanf("%d", &mode);

The & tells the compiler to send scanf a pointer to mode (i.e. its address) and not the actual value of mode. That way scanf can put update mode with the new scanned value.