QUESTION 42

QUESTION 42 

Given: 

 

23. Object [] myObjects = { 

24.        new Integer(12), 

25.        new String("foo"), 

26.        new Integer(5), 

27.        new Boolean(true) 

28. }; 

29. Arrays.sort(myObjects); 

30. for(int i=0; i<myObjects.length; i++) { 

31.    System.out.print(myObjects[i].toString()); 

32.    System.out.print(" "); 

33. } 

 

What is the result? 

 

A. Compilation fails due to an error in line 23. 

B. Compilation fails due to an error in line 29. 

C. A ClassCastException occurs in line 29. 

D. A ClassCastException occurs in line 31. 

E. The value of all four objects prints in natural order

Solution : C 

실행결과 

Exception in thread "main" java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Integer     

at java.lang.Integer.compareTo(Integer.java:37)     

at java.util.Arrays.mergeSort(Arrays.java:1144)     

at java.util.Arrays.sort(Arrays.java:1079)     

at main(Main.java:29) 

 

해석 : "String 이 담겨있기 때문에 정수형으로 바꿀 수 없다" 라는 오류메시지.