Program illustrating the use of Static Internal Variables in C

#include<stdio.h>
#include<conio.h>
int main()
{
 int i;
 clrscr();
 for(i=1;i<5;i++)
 {
  printsum();
 }
getch();
return 0;
}

int printsum()
{
 static int sum = 0;
 sum+=5;
 printf("%d\n",sum);
return 0;
}