test_static.c

#include <stdio.h>

void
func(  )
{
    static int x = 0;           // x is initialized only once across three calls of func()

    printf( " %d", x );         // outputs the value of x
    x = x + 1;
}

void
func2(  )
{
    static int x = 1;           // this is another static variable, but with different scope

    printf( " %d", x );
    x = x + 2;
}

int
main( int argc, char *const argv[] )
{
    printf( "func()  : " );
    func(  );                   // prints 0
    func(  );                   // prints 1
    func(  );                   // prints 2
    printf( "\nfunc2() : " );
    func2(  );                  // prints 1
    func2(  );                  // prints 3
    func2(  );                  // prints 5
    puts( "" );
    return 0;
}