若Animal是Cat,Dog的父类，则下列选项中，正确的是（）
A: Animal animal = new Cat();
B: Animal a = new Cat(); Cat cat = (Cat) a;
C: Animal animal = new Dog();
D: Cat cat = (Cat)new Dog();
A: Animal animal = new Cat();
B: Animal a = new Cat(); Cat cat = (Cat) a;
C: Animal animal = new Dog();
D: Cat cat = (Cat)new Dog();
举一反三
- 若Animal是Cat,Dog的父类，则下列选项中，正确的是（） A: Animal animal = new Cat(); B: Cat cat = (Cat)new Animal(); C: Animal animal = new Dog(); D: Cat cat = (Cat)new Dog();
- (7-1)定义了Animal类、Cat类和Dog类,则()代码段是正确的。classAnimal{};classCatextendsAnimal{}classDogextendsAnimal{} A: Dog[] a = new Dog[5];a[0] = new Cat(); B: Animal a = new Animal[5];a[0] = new Animal(); C: Dog[]a = new Dog[5];a[0] = new Animal(); D: Cat[]a = new Cat[5];a[0] = new Cat();
- 在前面几题的基础上，有子类Dog和Cat继承了父类Animal，如下空格的输出是以下哪个选项？dog = Dog(coco,small); cat = Cat(kawaii)>>> isinstance(dog, Animal)___________>>> isinstance(cat, Animal)___________>>> isinstance(dog, Dog)___________>>> isinstance(dog, Cat)____________
- Animal 是抽象类 ，Dog类和Cat类继承了Animal 。Animal dog = new Dog（）；的写法是否正确？
- 定义了Animal类、Cat类和Dog类，则（）代码段是正确的。classAnimal{};classCatextendsAnimal{ }classDogextendsAnimal{ } A: Dog[ ] ds=new Dog[5];ds[0]=new Animal(); B: Animal[ ] as=new Animal[5];as[0]=new Dog();