第一题：(答案:F)
Given the following method signatures from ArrayList:
boolean add(E e)
protected void removeRange(int fromIndexInclusive, int toIndexExclusive)
int size()
and given:
2. import java.util.*;
3. public class MyUtil extends ArrayList {
4. public static void main(String[] args) {
5. MyUtil m = new MyUtil();
6. m.add("w"); m.add("x"); m.add("y"); m.add("z");
7. m.removeRange(1,3);
8. System.out.print(m.size() + " ");
9. MyUtil m2 = new MyUtil2().go();
10. System.out.println(m2.size());
11. }
12. }
13. class MyUtil2 {
14. MyUtil go() {
15. MyUtil m2 = new MyUtil();
16. m2.add("1"); m2.add("2"); m2.add("3");
17. m2.removeRange(1,2);
18. return m2;
19. } }
What is the result?
A. 1 1
B. 1 2
C. 2 1
D. 2 2
E. An exception is thrown at runtime.
F. Compilation fails due to a single error.
G. Compilation fails due to multiple errors.
第二题：(答案:F)
Given:
1. public class Hose <E extends Hose> {
2. E innerE;
3. public static E doStuff(E e, Hose<E> e2) {
4. // insert code here
5. }
6. public E getE() {
7. return innerE;
8. } }
Which can be inserted, independently at line 4, for the code to compile? (Choose all that apply.)
A. return e;
B. return e.getE();
C. return e2;
D. return e2.getE();
E. return new Hose().getE();
F. Compilation fails regardless of which return is inserted.
请大家帮忙解释下原因，多谢啦！
