Updating a global variable in C

Question

I have a beginners C question. I want in the code below...

include <stdio.h>

void iprint();
int i=0;

int main()
{
  int j;

  for (j=0; j<50; j++)
    {
      iprint(i);
      printf("%d\n",i);
    }
}

void iprint(i)
{
  i +=1;
  //printf("%d\n",i); 
}

... the function "iprint" to update the value of i each time is it called, e.g. update i so that it can be used in main with the value 1 for iteration 2, and 3 for iteration 2 etc.

I accomplished this by changing the code to this:

 include <stdio.h>

int iprint();
int i=0;

int main()
{
  int j;

  for (j=0; j<50; j++)
    {
      i= iprint(i);
      printf("%d\n",i);
    }
}

int iprint(i)
{
  i +=1;
  //printf("%d\n",i); 
  return(i);
}

Do i have to return(i) to make that happen? The reason for asking, is that if i have a lot of functions using i, it's a bit annoying having to pass i between them. If you instead, somehow could update i like you update a global variable in matlab, that'd be great. Is it possible?

Answer 1

Use a pointer to point to the global variable. Change the pointer value. Thats it