SCJP 1.6版考題 001 - 修訂歷史

Ikk 於 2013年3月30日 (六) 09:13

2013-03-30T09:13:03Z

Ikk 於 2013年3月16日 (六) 05:37

2013-03-16T05:37:25Z

Ikk：新頁面:
Give...

2013-03-16T05:23:52Z

新頁面: Give...

新頁面

Given:


 1. public class Threads4{
 2. public static void main(String[] args){
 3. new Threads4.go();
 4. }
 5. public void go(){
 6. Runnable r = new Runnable(){
 7. public void run(){
 8. System.out.print("foo");
 9. }
 10. };
 11. Thread t = new Thread(r);
 12. t.start();
 13. t.start();
 14. }
 15.}
 
 What is the result?
 A. Compilation fails.
 B. An exception is thrown at runtime.
 C. The code executes normally and prints "foo";
 D. The code executes normally, but nothing is printed.



<div class="toccolours mw-collapsible mw-collapsed">
解答

----
<div class="mw-collapsible-content">
Ans: E 

 解說:
一個執行緒只能啟動一次 (t.start()只能下一次)，執行緒是物件，物件相關的動作發生問題是在執行時期產生例外，而不是編譯的錯誤。


</div></div>
{{SCJP 1.6版考題講解}}

@@ 行 2： / 行 2： @@
 </span></span>
-<br>Given:
+ <br>Given:
-−
-<span style="font-size:medium;"><span style="font-family: 'Helvetica Neue Light', HelveticaNeue-Light, 'Helvetica Neue', Helvetica, Arial, sans-serif; line-height: 19px; text-align: justify;">
+. public class Threads4{
-</span></span>
+. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;public static void main(String[] args){
+. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; new Threads4.go();
-. public class Threads4{
+. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }
+. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;public void go(){
-. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;public static void main(String[] args){
+. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Runnable r = new Runnable(){
+. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;public void run(){
-. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; new Threads4.go();
+. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;  &nbsp;System.out.print("foo");
+. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;}
-. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }
+. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;};
+. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Thread t = new Thread(r);
-. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;public void go(){
+. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; t.start();
+. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; t.start();
-. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Runnable r = new Runnable(){
+. &nbsp; &nbsp; &nbsp; &nbsp; }
+. &nbsp;}
-. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;public void run(){
+ <br>
+ What is the result?
-. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;System.out.print("foo");
+    A. Compilation fails.
+    B. An exception is thrown at runtime.
-. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;}
+    C. The code executes normally and prints "foo";
+    D. The code executes normally, but nothing is printed.
 <div class="toccolours mw-collapsible mw-collapsed">

@@ 行 1： / 行 1： @@
 <span style="font-size:medium;"><span style="font-family: 'Helvetica Neue Light', HelveticaNeue-Light, 'Helvetica Neue', Helvetica, Arial, sans-serif; text-align: justify;">
-<BR>Given:
+<br>Given:
-<span style="font-size:medium;"><span style="font-family: 'Helvetica Neue Light', HelveticaNeue-Light, 'Helvetica Neue', Helvetica, Arial, sans-serif; line-height: 19px; text-align: justify;">
+. &nbsp;}
-<BR>1. public class Threads4{
-<BR>2.   public static void main(String[] args){
+<br>
-<BR>3.     new Threads4.go();
-<BR>4.   }
+What is the result?
-</span></span>
+A. Compilation fails.

SCJP 1.6版考題 001 - 修訂歷史

Ikk 於 2013年3月30日 (六) 09:13

Ikk 於 2013年3月16日 (六) 05:37

Ikk：新頁面: Give...

Ikk：新頁面:
Give...