C - Does a static declaration reinitate the value when recalled?

golmschenk · 07-10-2010, 07:47 PM

I'm guesing not, but would a code of something like:

Code:

static int foo = 0;

when recalled reset the value to zero? Because although it's already been initialized and that doesn't happen again, does the = 0 part still effect it? Like I said, it doesn't make sense to me that it would but I decided I'd ask. Thanks!

easuter · 07-10-2010, 09:30 PM

When in doubt about small things like this in C, I like to write a quick program to test the problem (it generally saves tons more time than posting on a forum):

Code:

#include <stdio.h>

void test_static(int bar)
{
        static int foo = 0;
        printf("foo is: %d\n", foo);
        foo = bar;
        printf("foo is: %d\n", foo);
}

int main(void)
{
        test_static(2);
        test_static(100);

        return 0;
}

The output from that is:

Code:

foo is: 0
foo is: 2
foo is: 2
foo is: 100

I guess that answers your question

BTW, setting a static variable to zero is unnecessary, since K&R's book indicates that static variables get automatically initialized to zero.

golmschenk · 07-10-2010, 11:32 PM

Awesome. Perfect thanks. Yeah, I had considered writing a small program to test it, but I was working on another one and decided that someone would know on here so I could be lazy and not do it myself. Thanks a ton! Very descriptive answer.