相关考题

多项选择题 1. class Super {  2. private int a;  3. protected Super(int a) { this.a = a; }  4. }  .....  11. class Sub extends Super {  12. public Sub(int a) { super(a); }  13. public Sub() { this.a= 5; }  14. }  Which two, independently, will allow Sub to compile?()

单项选择题 1. class Pizza {  2. java.util.ArrayList toppings;  3. public final void addTopping(String topping) {  4. toppings.add(topping); 5. }  6. }  7. public class PepperoniPizza extends Pizza {  8. public void addTopping(String topping) {  9. System.out.println(”Cannot add Toppings”);  10. }  11. public static void main(String[] args) {  12. Pizza pizza = new PepperoniPizza();  13. pizza.addTopping(”Mushrooms”);  14. }  15. }  What is the result?()

单项选择题 public class Base {  public static final String FOO = “foo”;  public static void main(String[] args) {  Base b = new Base();  Sub s = new Sub();  System.out.print(Base.FOO);  System.out.print(Sub.FOO);  System.out.print(b.FOO);  System.out.print(s.FOO);  System.out.print(((Base)s).FOO);  } }  class Sub extends Base {public static final String FOO=bar;}  What is the result?()