多选题 Given:
2. class SafeDeposit {
3. private static SafeDeposit singleton;
4. public static SafeDeposit getInstance(int code) {
5. if(singleton == null)
6. singleton = new SafeDeposit(code);
7. return singleton;
8. }
9. private int code;
10. private SafeDeposit(int c) { code = c; }
11. int getCode() {return code; }
12. }
13. public class BeSafe {
14. // insert lots of code here
25. }
Which are true? (Choose all that apply.)

A、 Compilation fails.
B、 Class BeSafe can create many instances of SafeDeposit.
C、 Class BeSafe CANNOT create any instances of SafeDeposit.
D、 Class BeSafe can create only one instance of SafeDeposit.
E、 Class BeSafe can create instances of SafeDeposit without using the getInstance() method.
F、 Once class BeSafe has created an instance of SafeDeposit, it cannot change the value of the instance"s "code" variable.

【正确答案】 B、F

【答案解析】