SCJP 6.0認證教戰手冊考題.212--范型问题
Given:
3. import java.util.*;
4. public class Hancock{
5. //insert code here
6. list.add("foo");
7. }
8. }
Which two code fragments, inserted independently at line 5, will compile without warnings? (Choose two.)
A. public void addStrings(List list){
B. public void addStrings(List<String> list){
C. public void addStrings(List<? super String> list){
D. public void addStrings(List<? extends String> list){
答案:BC
选这两个对吗?只有D运行报错,其它的编译我没看到什么报警。