現(xiàn)有:
1. class Alpha { void m1() {} }
2. class Beta extends Alpha { void m2() { } }
3. class Gamma extends Beta { }
4.
5. class GreekTest {
6. public static void main(String [] args) {
7. Alpha [] a = {new Alpha(), new Beta(), new Gamma() };
8. for(Alpha a2 : a) {
9. a2.m1();
10. if (a2 instanceof Beta || a2 instanceof Gamma)
11. //insert code here
12. }
13. }
14. }
哪一行代碼插入到第11行,將編譯但是會(huì)在運(yùn)行時(shí)產(chǎn)生異常?()