Ikk：新頁面: Given: 1. public class A{ 2. public void method1(){ 3. B b = new B(); 4. b.method2(); 5. //more code here 6. } 7. } 1. public class B{ 2. public void method...

2013-03-30T03:19:04Z

新頁面: Given: 1. public class A{ 2. public void method1(){ 3. B b = new B(); 4. b.method2(); 5. //more code here 6. } 7. } 1. public class B{ 2. public void method...

新頁面

Given:
1. public class A{
2. public void method1(){
3. B b = new B();
4. b.method2();
5. //more code here
6. }
7. }
1. public class B{
2. public void method2(){
3. C c = new C();
4. c.method3();
5. //more code here
6. }
7. }

1. public class C{
2. public void method3(){
3. //more code here
4. }
5. }
And given:
25. try{
26. A a = new A();
27. a.method1();
28. }catch(Exception e){
29. System.out.print("an error occurred");
30. }

Which two statements are true if a NullPointerException is thrown on line 3 of class C? (Choose two.)
A. The application will crash.
B. The code on line 29 will be executed.
C. The code on line 5 of class A will execute.
D. The code on line 5 of class B will execute.
E. The exception will be propagated back to line 27.

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

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

<span style="font-size:medium;"> 解說:
當類別C中的第3行(method3)拋出NullPointerException 時 method3不正常結束後回到類別B的第4行(method2)，
而method2並沒有處理這個例外而不正常結束，又回到類別A的method1方法，回到method1的呼叫者27行(E)，
這個例外被28行的catch補捉到，執行第29行(B)
</span>
</div></div>
{{SCJP 1.6版考題講解}}

SCJP 1.6版考題 140 - 修訂歷史

Ikk：新頁面: Given: 1. public class A{ 2. public void method1(){ 3. B b = new B(); 4. b.method2(); 5. //more code here 6. } 7. } 1. public class B{ 2. public void method...