SCJP題庫第037題
21. abstract class C1{
22. public C1(){System.out.print(1);}
23. }
24. class C2 extends C1{
25. public C2(){System.out.print(2);}
26. }
27. class C3 extends C2{
28. public C3(){System.out.print(3);}
29. }
30. public class Ctest{
31. public static void main(String[] a){new C3();}
32. }
What is the result?
A. 3
B. 23
C. 32
D. 123
E. 321
F. Compilation fails.
G. An exception is thrown at runtime.
Ans:D
解說:
當一個建構子中若沒有對本身建構子 (this)或父類別建構子(super)的呼叫，建構子會有一個隱含的super()，即對父類別建構子的呼叫，因此，在建立C3物件時會呼叫C3的建構子，C3建構子會先叫用C2的建構子…
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