SCJP 1.6版考題 110

Given:
11. public static void test(Sting str){
12.   int check = 4;
13.   if(check = str.length()){
14.     System.out.print(str.charAt(check -= 1) + ", ");
15.   }else{
16.     System.out.print(str.charAt(O) + ", ");
17.   }
18. }
and the invocation:
21. test("four");
22. test("tee");
23. test("to");


What is the result?
  A. r, t, t,
  B. r, e, o,
  C. Compilation fails.
  D. An exception is thrown at runtime.

解答

---

Ans: C

解說:

13. if (check = str.length())  --> if (check == str.length()) {
在Java裏，所有條件式皆需是boolean型態，不能像在C/C++時代，以非零是true的觀念來看！
上式是因為check是整數型態，而check == str… 最終是boolean型態