CODEWITHSUNDEEP
javaabstract-classabstract
mingus2
mingus2

Reputation: 11

what should be given back in an abstract java method if the object given back will always be a different child object created as an extend?

lets say you got a parent class called block that has a lot of child classes and has the abstract method called rotate that should give you back a different child of block. what should the abstract method "give back" if its always a specific other child object ?

i tried working around it but it unfortunately doesn't work with other options trying to just change the parameter i needed to in the method implementation of the child classes.

I have tried looking up any solutions or examples for this but i'm not quite sure for what to actually search.

lets say

public class Block{
     abstract public void rotate();
}

but instead of void what should i do to give back a different object extending block. if i got the public class T extends Block{} and the method rotate should give back the object from public class Ttilt extends Block{}.

Upvotes: 1

Views: 38

Answers (1)

MorganS42
MorganS42

Reputation: 662

The solution should implement generics. This would look like the following:

public abstract class Parent<T extends Parent<T>> {
    ...
    abstract T method();
    ...
}

Your child class would look like:

public class ChildA<ChildA> {
    ...
}

This will let you call method() through any of the child classes and that method will return an instance of that specific child class.

Upvotes: 0

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