Module 2- 类、接口以及枚举.docxVIP

Copyright Tarena Corporation,2008.All rights reservedModule 2- 类、接口以及枚举一、选择题： Question 1Given:11. public interface Status {12. /* insert code here */ int MY_VALUE = 10;13. }Which three are valid on line 12? (Choose three.)A. finalB. staticC. nativeD. publicE. privateF. abstractG. protectedAnswer: ABDQuestion 2Given:10. class Foo {11. static void alpha() { /* more code here */ }12. void beta() { /* more code here */ }13. }Which two are true? (Choose two.)A. Foo.beta() is a valid invocation of beta().B. Foo.alpha() is a valid invocation of alpha().C. Method beta() can directly call method alpha().D. Method alpha() can directly call method beta().Answer: BCQuestion 3Click the Exhibit button.11. class Payload {12. private int weight;13. public Payload(int wt) { weight = wt; }1 4 . public Payload( ) {}1 5 . public void setWeight(mt w) { weight = w; }1 6 . public String toString { return Integer.toString(weight); }1 7 . }1 8 .1 9 . public class TestPayload {20 . static void changePayload(Payload p) {2 1 . /* insert code here */Copyright Tarena Corporation,2008.All rights reserved2 2 . }2 3 .2 4 . public static void main(String[] args) {2 5 . Payload p = new Payload();2 6 . p.setWeight(1024);2 7 . changePayload(p);2 8 . System.out.println( The value of p is + p);2 9 . }30 . }Which statement, placed at line 2 1 , causes the code to print “ Thevalue of p is 420. ” ?A. p.setWeight(420);B. p.changePayload(420);C. p = new Payload(420);D. Payload.setWeight(420);E. p = Payload.setWeight(420);F. p = new Payload();p.setWeight(420);Answer: AQuestion 4Click the Exhibit button.1. public class Item {2. private String desc;3. public String getDescription() { return desc; }4. public void setDescription(String d) { desc = d; }5.6. public static void modifyDesc(Item item, String desc) {7. item = new Item();8. item.setDescription(desc);9. }10. public static void main(String[] args) {11. Item it = new Item();12. it.setDescription( Gobstopper );13. Item it2 = new Item();14. it2.setDescrip