method does not override or implement a method from a supertype - for Override Error

Question about the task

OOP: Animal inheritance

Java Core, Level 5, Lesson 2

Under discussion

Why am I getting this error?? Thanks

package com.codegym.task.task15.task1502;

/*
OOP: Animal inheritance

*/

public class Solution {
    // Add the Goose and Dragon classes here

    public static class Goose extends SmallAnimal {


        @Override
        public static String getSize() {
            return "A goose is small, " + SmallAnimal.getSize();
        }
    }

    public static class Dragon extends BigAnimal {

        @Override
        public static String getSize() {
            return "A dragon is big, " + BigAnimal.getSize();
        }
    }

    public static void main(String[] args) {

    }

    public static class BigAnimal {
        public static String getSize() {
            return "like a dinosaur";
        }
    }

    public static class SmallAnimal {
        public static String getSize() {
            return "like a cat";
        }
    }
}

1. Create a public static Goose class.
2. Create a public static Dragon class.
3. Make the Goose class inherit either BigAnimal or SmallAnimal. Think about which would be more logical.
4. Make the Dragon class inherit either BigAnimal or SmallAnimal. Think about which would be more logical.
5. Make the Goose and Dragon classes override the String getSize() method and make its visibility as wide as possible.
6. In the Goose class, the getSize method should return "A goose is small, " + <parent class>.getSize().
7. In the Dragon class, the getSize method should return "A dragon is big, " + <parent class>.getSize().

Requirements:

The Goose class must be inside the Solution class and must be static.
The Dragon class must be inside the Solution class and must be static.
The Goose class must be a descendant of the SmallAnimal class.
The Dragon class must be a descendant of the BigAnimal class.
In the Goose class, the getSize method must be overridden. It should return a string formatted as follows: "A goose is small, " + <parent class>.getSize().
In the Dragon class, the getSize method must be overridden. It should return a string formatted as follows: "A dragon is big, " + <parent class>.getSize().
The visibility of the overridden getSize methods in the Goose and Dragon classes must be made as wide as possible.

package com.codegym.task.task15.task1502; /* OOP: Animal inheritance */ public class Solution { // Add the Goose and Dragon classes here public static class Goose extends SmallAnimal { @Override public static String getSize() { return "A goose is small, " + SmallAnimal.getSize(); } } public static class Dragon extends BigAnimal { @Override public static String getSize() { return "A dragon is big, " + BigAnimal.getSize(); } } public static void main(String[] args) { } public static class BigAnimal { public static String getSize() { return "like a dinosaur"; } } public static class SmallAnimal { public static String getSize() { return "like a cat"; } } }

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Guadalupe Gagnon

Level 37 , Tampa, United States

8 March 2021, 21:42

static methods can not be over ridden. Consider removing that keyword from all the getSize() methods. Once that is fixed, the over ridden getSize() methods in Goose and Dragon cannot call the parent classes getSize() methods in a static fashion (that is by using the classname.methodname(), such as BigAnimal.getSize()). You are going to need to use the proper keyword that tells the compiler to use the parent class method, example:

return "A dragon is big, " + /*{keyword}*/.getSize();

Zach

Level 22 , Fort Collins, United States

9 March 2021, 19:07

I run this and it works (also without Solution. at the beginning). I thought the point of static methods was that you could call them without having to create objects. I am still very confused by static methods.... What other keywords could you use if you haven't created any objects. And you arent using this, right? thanks

package com.codegym.task.task15.task1502;

/*
OOP: Animal inheritance

*/

public class Solution {
    // Add the Goose and Dragon classes here

    public static class Goose extends SmallAnimal {


        public static String getSize() {
            return "A goose is small, " + Solution.SmallAnimal.getSize();
        }
    }

    public static class Dragon extends BigAnimal {

        // @Override
        public static String getSize() {
            return "A dragon is big, " + Solution.BigAnimal.getSize();
        }
    }

    public static void main(String[] args) {

        Goose goose = new Goose();
        System.out.println(goose.getSize());

    }

    public static class BigAnimal {
        public static String getSize() {
            return "like a dinosaur";
        }
    }

    public static class SmallAnimal {
        public static String getSize() {
            return "like a cat";
        }
    }
}

Guadalupe Gagnon

Level 37 , Tampa, United States

9 March 2021, 19:35

The task says: "Make the Goose and Dragon classes override the String getSize() method and make its visibility as wide as possible" In Java, static methods are final and can not be over ridden. Because of this the methods in this task, having to over ride the parent methods, can not be static. Making them static means that this task requirement can't pass. There is a (*HINT HINT*) super keyword to use that refers to the parent classes implementation of the method being over ridden.