SCJP 1.6版考題 085
出自 陳富國維基館
11. class Animal{public String noise(){return "peep";}}
12. class Dog extends Animal{
13. public String noise(){return "bark";}
14 }
15. class Cat extends Animal{
16. public String noise(){return "meow";}
17. }
...
30. Animal animal = new Dog();
31. Cat cat = (Cat)animal;
32. System.out.println(cat.noise());
What is the result?
A. peep
B. bark
C. meow
D. Compilation fails.
E. An exception is thrown at runtime.
解答
Ans: E
解說:
animal 是指向Dog物件， Cat類別與Dog類別二者間無繼承關係，不可以指向animal 所指向的Dog物件
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