我对java继承有一个非常基本的了解。有人可以解释一下应该怎么做？

Posted 2021-03-30

在我最近的编码轮中提出了这个问题。

我不得不打印以下几行：

My name is Fastfood.
My name is Fruits.
Our superclass is Food
I'm serving Fastfood
I'm serving Fruit

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class foodFactory extends Solution{

}
class Food extends Solution{

}


class Solution
{
    public static void main (String[] args) throws java.lang.Exception
    {
        // your code goes here
        foodFactory myFoods = new foodFactory();
        Food food1 = myFoods.getFood("Fastfood");
        Food food2 = myFoods.getFood("Fruits");
        System.out.println("My name is: " + food1.getClass().getName());
        System.out.println("My name is: " + food2.getClass().getName());
        System.out.println("Our superclass is: " + food1.getClass().getSuperclass.getName());
        food1.servesFood();
        food2.servesFood();

    }
}

答案

public class Solution2 {
    public static void main(String[] args) {
        FoodFactory myFoods = new FoodFactory();
        Food food1 = myFoods.getFood("FastFood");
        Food food2 = myFoods.getFood("Fruit");
        System.out.print("My name is: " + food1.getClass().getName());
        System.out.print("My name is: " + food2.getClass().getName());
        System.out.print("Our superclass is: " + food1.getClass().getSuperclass().getName());
        food1.serveFood();
        food2.serveFood();
    }
}

class Food {
    String name;
    public void serveFood() {
        // TODO Auto-generated method stub
        System.out.print("I'm serving " + name);
    }
}
class FoodFactory extends Food {
    String name;
    public Food getFood(String string) {
        if (string.equals("FastFood")) {
            Food f = new FastFood();
            f.name = string;
            return f;
        } else {
            Food f = new Fruit();
            f.name = string;
            return f;
        }
    }
}

class FastFood extends Food {
}

class Fruit extends Food {
}

另一答案

class foodFactory extends HelloWorld{
    Food ff = new Food();
    public Food getFood(String s){
        if(s.equals("Fastfood"))
            return new FastFood();
        else 
            return new Fruits();

    }
    public void servesFood(){

    }
}
class Food extends HelloWorld{
public void servesFood(){
        System.out.println("I am serving"+this.getClass().getName());
    }
}
class Fruits extends Food{}
class FastFood extends Food{}
public class HelloWorld{


    public static void main (String[] args) throws java.lang.Exception
    {
        // your code goes here
        foodFactory myFoods = new foodFactory();
        Food food1 = myFoods.getFood("Fastfood");
        Food food2 = myFoods.getFood("Fruits");
        System.out.println("My name is: " + food1.getClass().getName());
        System.out.println("My name is: " + food2.getClass().getName());
        System.out.println("Our superclass is: " + food1.getClass().getSuperclass().getName());
        food1.servesFood();
        food2.servesFood();

    }

}

另一答案

我尝试了很多，经过一个小小的修改，我得到了解决方案

class FoodFactory  extends Solution
{
    public Food getFood(String string) 
    {
        return new Food(string);
    }
}

class Food extends Solution
{
    String name=null;
    public Food(String string) 
    {
        this.name=string;
    }
    public void servesFood() 
    {
        System.out.println("I'm serving "+this.name);
    }
}

class Solution
{
    public static void main (String[] args) throws java.lang.Exception
    {
        FoodFactory myFoods = new FoodFactory();
        Food food1 = myFoods.getFood("Fastfood");
        Food food2 = myFoods.getFood("Fruits");
        System.out.println("My name is: " + food1.name);
        System.out.println("My name is: " + food2.name);
        System.out.println("Our superclass is: " + food1.getClass().getName());//modification
        food1.servesFood();
        food2.servesFood();
    }}

另一答案

我测试了它，它按预期工作。

`class FoodFactory extends Food {
    public Food getFood(String string) {
        if (string.equals("Fruit")) {
            return new Fruit("Fruit");
        } else {
            return new FastFood("FastFood");
        }
    }
}

class Fruit extends Food {
    public Fruit(String name1) {
        super.name = name1;
    }
}

class FastFood extends Food {
    public FastFood(String name1) {
        super.name = name1;
    }
}

class Food {
    public String name = null;
    public Food() {

    }
    public Food(String string) {
        this.name = string;
    }
    public void servesFood() {
        System.out.println("I'm serving " + this.name);
    }
}

class Solution1 {
    public static void main(String[] args) throws java.lang.Exception {
        FoodFactory myFoods = new FoodFactory();
        Food food1 = myFoods.getFood("FastFood");
        Food food2 = myFoods.getFood("Fruit");
        System.out.println("My name is: " + food1.getClass().getName());
        System.out.println("My name is: " + food2.getClass().getName());
        System.out.println("Our superclass is: "
                + food1.getClass().getSuperclass().getName());// modification
        food1.servesFood();
        food2.servesFood();
    }
}`

另一答案

类似于给定的答案，但与抽象的食品类。

class FoodFactory extends Food {
    public Food getFood(String string) {
        if (string.equals("Fruit")) {
            return new Fruit();
        } else if (string.equals("FastFood"){
            return new FastFood();
        }
        return null;
    }

    @Override
    public void servesFood() {

    }
}

class Fruit extends Food {
    @Override
    public void servesFood() {
        System.out.println("I'm serving " + getClass().getName());
    }
}

class FastFood extends Food {
    @Override
    public void servesFood() {
        System.out.println("I'm serving " + getClass().getName());
    }
}

abstract class Food {
    public abstract void servesFood();
}

class Solution1 {
    public static void main(String[] args) throws java.lang.Exception {
        FoodFactory myFoods = new FoodFactory();
        Food food1 = myFoods.getFood("FastFood");
        Food food2 = myFoods.getFood("Fruit");
        System.out.println("My name is: " + food1.getClass().getName());
        System.out.println("My name is: " + food2.getClass().getName());
        System.out.println("Our superclass is: "
                + food1.getClass().getSuperclass().getName());// modification
        food1.servesFood();
        food2.servesFood();
    }
}

另一答案

我检查了答案，但是我做了这个结果，注意目标是带有所有参数的复合短语。在许多情况下，答案必然只是在标记的摘录之后，并且从不使用如下所述的整个课程。

编译并取得成功！

/*
 * My name is: Fastfood
 * My name is: Fruits
 * Our superclass is: Food
 * I'm serving Fastfood
 * I'm serving Fruits
 */

class Solution {
    public static void main(String[] argh) {
        foodFactory myFoods = new foodFactory();
        Food food1 = myFoods.getFood("Fastfood");
        Food food2 = myFoods.getFood("Fruits");
        System.out.println("My name is: " + food1.getClass().getName());
        System.out.println("My name is: " + food2.getClass().getName());
        System.out.println("Our superclass is: " + food1.getClass().getSuperclass().getName());
        food1.serveFood();
        food2.serveFood();
    }
}

// attention: from here you will have the correct use
class foodFactory extends Solution {
    public Food getFood(String food) {
        if (food.equals("Fastfood")) {
            return new Fastfood();
        } else {
            return new Fruits();
        }
    }
}

class Food extends Solution {
    public void serveFood() {
        System.out.println("I'm serving " + this.getClass().getName());
    }
}

class Fruits extends Food {
}

class Fastfood extends Food {
}