Cat is-a Animal
Cat is-a Jumper
Dog is-a Animal
Dog is-a Jumper
Cat has-a Animal
Beagle has-a Tail
Beagle has-a Jumper
第1题:
下列程序片段中,能通过编译的是( )。
A.public abstract class Animal{ public void speak;}
B.public abstract class Animal{ public void speak{);}
C.public class Animal{ pubilc abstract void speak;}
D.public abstract class Animal{ pubile abstract void speak{};}
第2题:
Which three demonstrate an “is a” relationship?()
第3题:
下列程序片段中,能通过编译的是
A.public abstract class Animal{ public void speak();}
B.public abstract class Animal{ public void speak(){}}
C.public class Animal{ public abstract void speak();}
D.public abstract class Animal{ public abstract void speak(){}}
第4题:
现有: interface Animal { void eat () ; } //insert code here public class HouseCat extends Feline { public void eat() { } } 和五个申明 abstract class Feline implements Animal { } abstract class Feline implements Animal { void eat () ; } abstract class Feline implements Animal { public void eat();} abstract class Feline implements Animal { public void eat() {} } abstract class Feline implements Animal { abstract public void eat();} 结果为:()
第5题:
class Animal{ Animal getOne(){return new Animal();}} class Dog extends Animal{ //insert code here } class AnimalTest{ public static void main(String[] args){ Animal[] animal={ new Animal(), new Dog()}; for(Animal a:animal){ Animal x= a.getOne(); } } } 和代码: 3a.Dog getOne() { return new Dog();} 3b.Animal getOne() { return new Dog();} 第3行中插入的哪项编译且运行无异常?
第6题:
10. interface Jumper { public void jump(); } ...... 20. class Animal {} ...... 30. class Dog extends Animal { 31. Tail tail; 32. } ...... 40. class Beagle extends Dog implements Jumper { 41. public void jump() { } 42. } ....... 50. class Cat implements Jumper { 51. public void jump() { } 52. } Which three are true?()
第7题:
interface Data { public void load(); } abstract class Info { public abstract void load(); } Which class correctly uses the Data interface and Info class?()
第8题:
下列程序片段中,能通过编译的是( )。
A.public abstract class Animal{public void speak( );}
B.public abstract class Animal{public void speak( ){};}
C.public class Animal{pubilc abstract void speak( );}
D.public abstract class Animal{pubile abstract void speak( ){};}
第9题:
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.printIn(cat.noise()); What is the result?()
第10题:
现有: interface Data {public void load();} abstract class Info {public abstract void load();} 下列类定义中正确使用Data和Info的是哪项?()