static variables

what is static variables?

I know global variables and local variables .. but static not sure..

Is it the same as local variables?

Static variables will remain the same after a fuction had been exited and then reentered.

also check out This

An example:

Code:

---

#include <iostream>

void foo()
{
  static int i;
  std::cout << i++ << std::endl;
}

int main()
{
  for (int i = 0; i < 10; i++)
    foo();
}

---

Ok..
Im reading bjarne stroustrup's book..

and he asks:

CH 6. EX 21.
CONVERT THE DESK CALCULATOR TO USE A SYMBOL STRUCTURE INSTEAD OF USING THE
STATIC VARIABLES number_value AND string_value.

now what does he mean by symbol structure...
especially since those var contains numbers and word like "pi"..

its nothing like + = or anything like that how can I use symbol to contain/equal "25" or "mother"?

Im kinda lost there..

a better example

Code:

---

#include <stdio.h> /* I like C  :) */

int main(void)
{
  int i =0;
  for(;i < 10 ;i++)
  {
    printf("i in main() is %d", i);
    foo();
    }
return 0;
}

void foo(void)
{
  static i = 999;
  printf("static i is %d", i);
  i--;
}

---

that will just show that statics are local variables, and the remain the same after a function ends.