第83題

Given:
10. interface Foo{
11. int bar();
12. }
13.
14. public class Beta {
15.
16. class A implements Foo{
17. public int bar(){return 1;}
18. }
19.
20. public int fubar(Foo foo){return foo.bar();}
21.
22. public void testFoo(){
23.
24. class A implements Foo{
25. public int bar() {return 2;}
26. }
27.
28. System.out.println(fubar(new A()));
29. }
30.
31. public static void main(String[] argv){
32. new Beta().testFoo();
33. }
34. }
Which three statements are true? (Choose three.)

A. Compilation fails.
B. The code compiles and the output is 2.
C. If lines 16, 17 and 18 were removed, compilation would fail.
D. If lines 24, 25 and 26 were removed, compilation would fail.
E. If lines 16, 17 and 18 were removed, the code would compile and the output would be 2.
F. If lines 24, 25 and 26 were removed, the code would compile and the output would be 1.
答案：BEF
參考：7-6 介面、8-5 內部類別
-------------------------------------------------
32. new Beta().testFoo();
>>22. public void testFoo(){
>>28. System.out.println(fubar(new A()));
>>20. public int fubar(Foo foo){return foo.bar();}
>>24. class A implements Foo{
>>25. public int bar() {return 2;} //B. The code compiles and the output is 2.

E. If lines 16, 17 and 18 were removed, the code would compile and the output would be 2.
lines 16, 17 and 18 和選項b無關故一樣output is 2

lines 24, 25 and 26 移除的話
>>28. System.out.println(fubar(new A()));
>>16. class A implements Foo{
>>17. public int bar(){return 1;} //output would be