#include <iostream>

using namespace  std ; 

class  Banana
{
	public:

	static int id ; 

	Banana(void)
	{
		id++ ; 
		cout << "this is a test: " << id << endl ; 
	}
};

//类中的静态变量，必须在全局定义
int Banana::id = 0 ; 

int main(void)
{

	Banana a  , b , c , d , e , f , g;

	return 0 ; 
}

运行结果：