Static vs. Automatic

/** version 1 - automatic variables **/


#include <stdio.h>

void counter(void);

int main(void)
{
  int i;

  for (i = 0; i < 10; i++)
    counter();

  return (0);
}


void counter(void)
{
  int count = 0;

  printf("\nCount = %d", count);
  count++;
}

/********************************************/
OUTPUT from static.c version 1

Count = 0
Count = 0
Count = 0
Count = 0
Count = 0
Count = 0
Count = 0
Count = 0
Count = 0
Count = 0



/** version 2 - static variables **/


#include <stdio.h>

void counter(void);

int main(void)
{
  int i;

  for (i = 0; i < 10; i++)
    counter();
 
  return (0);
}


void counter(void)
{
  static int count = 0;

  printf("\nCount = %d", count);
  count++;
}

/*********************************************/
OUTPUT from static2.c

Count = 0
Count = 1
Count = 2
Count = 3
Count = 4
Count = 5
Count = 6
Count = 7
Count = 8
Count = 9