單項(xiàng)選擇題
現(xiàn)有:
1.class SuperFoo{
2.SuperFoo doStuff (int x) {
3.return new SuperFoo();
4. }
5. }
6.
7. class Foo extends SuperFoo {
8. //insert code here
9. }
和四個(gè)聲明:
Foo doStuff (int x) { return new Foo(); }
Foo doStuff (int x) { return new SuperFoo(); }
SuperFoo doStuff(int x) { return new Foo(); }
SuperFoo doStuff(int y) { return new SuperFoo(); }
分別插入到第8行,有幾個(gè)可以通過(guò)編澤?()