Undefined reference to static variable
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/272900/c-undefined-reference-to-static-class-member">C++: undefined reference to static class member</a>  </p>
</blockquote>



<p>I'm using MinGW. Why static variable is not working  </p>

<pre><code>[Linker error] undefined reference to `A::i' 

#include &lt;windows.h&gt;

    class A { 
        public:     
        static int i;
        static int init(){

            i = 1;  

        }

    };

int WINAPI WinMain (HINSTANCE hThisInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpszArgument,
                    int nFunsterStil){
    A::i = 0;
    A::init();

    return 0;
}
</code></pre>
