请教大家!
Q50
Given the following interface definition, which definitions are valid?
interface I {
void setValue(int val);
int getValue();
}
DEFINITION A:
(a) class A extends I {
int value;
void setValue(int val) { value = val; }
int getValue() { return value; }
}
DEFINITION B:
(b) interface B extends I {
void increment();
}
DEFINITION C:
(c) abstract class C implements I {
int getValue() { return 0; }
abstract void increment();
}
DEFINITION D:
(d) interface D implements I {
void increment();
}
DEFINITION E:
(e) class E implements I {
int value;
public void setValue(int val) { value = val; }
}
1) Definition A.
2) Definition B.
3) Definition C.
4) Definition D.
5) Definition E.
答案是2,3
我认为是1,2,3
Definition A中,A继承了B,且把B中的所有abstract都实现了,不是对的吗?