超星 - 4.4多态过关练习

单选题

若Animal 是Cat,Dog的父类，则下列选项中，错误的是（）

Animal animal = new Cat();
B. Cat cat = new Cat();
C. Animal animal = new Dog();
D. Cat cat = (Cat)new Dog();

多选题

A. Cat cat = (Cat)new Animal();
B. Animal a = new Cat(); Cat cat = (Cat) a;
C. Animal animal = new Cat();
D. Animal a = new Dog(); Cat cat = (Cat) a;