Question 18
Given:
10. interface A { public int getValue() }
11. class B implements A {
12. public int getValue() { return 1; }
13. }
14. class C extends B {
15. // insert code here
16. }
Which three code fragments, inserted individually at line 15, make use
of polymorphism? (Choose three.)
A. public void add(C c) { c.getValue(); }
B. public void add(B b) { b.getValue(); }
C. public void add(A a) { a.getValue(); }
D. public void add(A a, B b) { a.getValue(); }
E. public void add(C c1, C c2) { c1.getValue(); }
帮忙分析一下
b、c、d分别用多态的哪些特性??
A 不正确,不正确的原因
B,C,D正确,原因是什么?
感谢