Ikk：新頁面: Given: 11. public static Iterator reverse(List list){ 12. Collections.reverse(list); 13. return list.iterator(); 14. } 15. public static void main(String[] args){ 16. List...

2013-03-30T00:15:26Z

新頁面: Given: 11. public static Iterator reverse(List list){ 12. Collections.reverse(list); 13. return list.iterator(); 14. } 15. public static void main(String[] args){ 16. List...

新頁面

Given:
11. public static Iterator reverse(List list){
12. Collections.reverse(list);
13. return list.iterator();
14. }
15. public static void main(String[] args){
16. List list= new ArrayList();
17. list.add("1"); list.add("2"); list.add("3");
18. for(Object obj : reverse(list))
19. System.out.print(obj + ", ");
20. }

What is the result?

A. 3, 2, 1,
B. 1, 2, 3,
C. Compilation fails.
D. The code runs with no output.
E. An exception is thrown at runtime.

<div class="toccolours mw-collapsible mw-collapsed">
<span style="font-size:medium;">解答</span>

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<div class="mw-collapsible-content">
<span style="font-size: medium;">Ans: C </span>

<span style="font-size:medium;"> 解說:
Iterator不能用enhanced for，要用一般的for
import java.util.*;
class test{
public static Iterator reverse(List list){
Collections.reverse(list);
return list.iterator();
}
public static void main(String[] args){
List<String> list= new ArrayList<String>();
list.add("1"); list.add("2"); list.add("3");
Iterator it = reverse(list);
for(;it.hasNext();)
System.out.print(it.next().toString() + ", ");
}
}

</span>
</div></div>
{{SCJP 1.6版考題講解}}

SCJP 1.6版考題 198 - 修訂歷史

Ikk：新頁面: Given: 11. public static Iterator reverse(List list){ 12. Collections.reverse(list); 13. return list.iterator(); 14. } 15. public static void main(String[] args){ 16. List...