java学校上个学期的题,有没有谁能给个代码完整的标准答案参考参考吗

img

public interface   Animal{   
   void eat();
   void sleep();
}

public class Cat implements  Animal{
   public void eat(){
       System.out.println("Cat can  eat");
   }
  public void sleep(){
       System.out.println("Cat can  sleep");
   }
}
public class Dog  implements  Animal{
   public void eat(){
       System.out.println("Dog can eat");
   }
   public void sleep(){
       System.out.println("dog can sleep");
   }
}
public interfaceDemo{
   public static void main(String args[]){
     Cat a=new Cat();
     a.eat();
     a.sleep();
     Dog p= new Dog();
     p.eat();
     p.sleep();
  }
}

这个主要是java类和对象的问题,根据需要创建类和对象就行了

img

给你分析你的问题吧。
你的问题在于对接口和实现类之间的关系不太理解。
首先接口中只是定义方法,没有具体的实现。
类实现接口,所谓实现就是实现接口中的方法,也就是给出接口中定义方法的具体实现。

接口:定义eat()方法、 sleep()方法。
即
public interface Animal {
    public void eat();    
    public void sleep();
}
两个实现类实现接口:**注意实现方法上要加@Override注解**
Cat类:
public class Cat implements Animal {
@Override
public void eat(){
       System.out.println("猫可以吃东西");
   }
@Override
  public void sleep(){
       System.out.println("猫可以睡觉");
   }
}
Dog类同理:只是具体实现内容不一样。
public class Dog implements Animal {
@Override
public void eat(){
       System.out.println("狗可以吃东西");
   }
@Override
  public void sleep(){
       System.out.println("狗可以睡觉");
   }
}
测试类:创建cat和dog类对象,并调用其中的方法。
public interfaceDemo{
   public static void main(String args[]){
     Cat cat=new Cat();
     cat.eat();
     cat.sleep();
     Dog dog= new Dog();
     dog.eat();
     dog.sleep();
  }
}

我有个功能一样的程序。

public interface Animal {
    public  void eat(String s);

    public  void sleep(String s);
}

public class Cat implements Animal{

    @Override
    public void eat(String s) {
        System.out.println("Cat eat");
    }

    @Override
    public void sleep(String s) {
        System.out.println("Cat sleep");
    }
}

public class Dog implements Animal{
    @Override
    public void eat(String s) {
        System.out.println("Dog eat");
    }

    @Override
    public void sleep(String s) {
        System.out.println("Dog sleep");
    }
}

public class InterfaceDemo {
    public static void main(String[] args){
        Cat cat = new Cat();
        cat.eat( "eat" );
        cat.sleep( "sleep" );

        Dog dog = new Dog();
        dog.eat( "eat" );
        dog.sleep( "sleep" );
    }
}

解决疑惑了吗

Animal.java文件:

public interface Animal {
    public void eat();
    public void sleep();
}

Cat.java文件:

public class Cat implements Animal{

    @Override
    public void eat() {
        System.out.println("Cat eat!");    
    }

    @Override
    public void sleep() {
        System.out.println("Cat sleep!");
    }    
}

Dog.java文件:

public class Dog implements Animal{
    @Override
    public void eat() {
        System.out.println("Dog eat!");    
    }

    @Override
    public void sleep() {
        System.out.println("Dog sleep!");
    }    
}

TestAnimal.java文件:


public class TestAnimal {
    
public static void main(String args[]) {
    Cat ct = new Cat();
    ct.eat();
    ct.sleep();
    
    Dog dog = new Dog();
    dog.eat();
    dog.sleep();
    
    }

}

public interface Animal {

/**
 * 吃食物方法
 * @param food 食物名称
 */
public void eat(String food);

/**
 * 睡眠方法
 * @param hours  睡眠时长
 */
public void sleep(int hours);

}

public class Dog implements Animal {

@Override
public void eat(String food) {
    // 输出:类名+方法名+食物名称
    System.out.println("Dog eat " + food);
}

@Override
public void sleep(int hours) {
    // 输出:类名+方法名+睡觉时长
    System.out.println("Dog sleep " + hours + " hours at night");
}

}

public class Cat implements Animal {

@Override
public void eat(String food) {
    // 输出:类名+方法名+食物名称
    System.out.println("Cat eat " + food);

}

@Override
public void sleep(int hours) {
    // 输出:类名+方法名+睡觉时长
    System.out.println("Cat sleep " + hours + " hours during the day");

}

}

public class IntrefaceDemo {

public static void main(String[] args) {
    Dog dog = new Dog();
    dog.eat("bone");
    dog.sleep(6);
    System.out.println();
    Cat cat = new Cat();
    cat.eat("fish");
    cat.sleep(6);
}

}

运行结果:
Dog eat bone
Dog sleep 6 hours at night

Cat eat fish
Cat sleep 6 hours during the day