java练习本(2019-07-09)

public class Test {
   static boolean flag;
   public static void main(String[] args) {
       System.out.println(flag);
  }
}

public class Test {
   public static void main(String[] args) {
       Car car1 = Car.getInstance();
       Car car2 = Car.getInstance();
       System.out.println(car1 == car2);
  }
}

class Car{
   private static  Car car = new Car();

   private Car(){}

   public static Car getInstance(){
       return car;
  }
}