记录类的个数

源代码：

package 类的统计;
class Num{
    private static int n;
    public Num() {
        n++;
    }
    public static int get()
    {
        return n;
    }
}
public class Tongji {
public static void main(String[ ]args) {
    Num n1=new Num();
    Num n2=new Num();
    System.out.println("创建对象的个数为："+Num.get());
}
}