Use of Static Variables from Outside of Defining Class

[Chris Portka]

How can I modify static variables from outside the class they're
defined in? It doesn't work if I try to access them from a function,
from an instantiated object, or from the class itself. Here's an
example:
MAIN:
#include "test"

int main()
{
Test t;
//All of these give "unresolved external symbol"
t.x = 1;
t.setX(1);
Test::x = 1;
Test::setX(1);
}

TEST:
class Test
{
public:
static int x;
static void setX(int z) { x = z; }
};

 

[Robert Bauck Hamar]

How can I modify static variables from outside the class they're
defined in? It doesn't work if I try to access them from a function,
from an instantiated object, or from the class itself. Here's an
example:
MAIN:
#include "test"

put
int Test::x;
about here.

int main()
{
Test t;
//All of these give "unresolved external symbol"
t.x = 1;
t.setX(1);
Test::x = 1;
Test::setX(1);
}

TEST:
class Test
{
public:
static int x;

This is only a declaration. You need a definition too.

 

[CTG]

Where is your constructor destructor defined?

 

[David Harmon]

On 5 Dec 2006 16:45:23 -0800 in comp.lang.c++, "Chris Portka"

//All of these give "unresolved external symbol"
t.x = 1;
t.setX(1);
Test::x = 1;

This issue is covered in Marshall Cline's C++ FAQ. See the topic
"[10.11] Why are classes with static data members getting linker
errors?" It is always good to check the FAQ before posting. You can
get the FAQ at:
http://www.parashift.com/c++-faq-lite/