CODEWITHSUNDEEP
javaoopinheritance
ngesh
ngesh

Reputation: 13501

Same getters and setters in 2 child classes..?

I'm not that good OO design .. so please bear with me..

I have Class A, And 2 classes which extend A. But both of them have same fields.. So what is better, to have getter / setters in A or to have same getter / setters in both child classes.. Or is there a better a way to do this..?

this is what i have done (mock)..

 class A{

    private int x;

    protected A(int x){
    this.x = x;
    }

    public static A createA(id a, int x){
    switch(a){
    case 0: 
    return new C(x);
    break;
    //so on

    }


    public int getX(){
    return x;
   }

    }

Thanks..

Upvotes: 0

Views: 962

Answers (2)

Theodoros Chatzigiannakis
Theodoros Chatzigiannakis

Reputation: 29213

Let's say your classes are A (the parent) and B and C (the children). You say that B and C have some fields that are the same.

Ask yourself: If you had another class D, child of A, would it have those fields too regardless of its specific functionality?

  • If the answer is yes, then the existence of these fields in both subclasses is definitely not a coincidence, so you should probably define them in A, because it means that they have these members precisely because they inherit from A.

  • If the answer is no, the existence of these fields in the subclasses may or may not be a coincidence. So, you should ask yourself: Even if D doesn't have these fields, does their existence in both B and C look more than just a coincidence? Do these classes share something that D, another child of A, simply doesn't happen to share?

    • If yes, then consider a new class E that extends A, with E defining these common members and then make B and C children of E instead of A.

    • If not (if it looks to you like just a coincidence), then leave your structure as it is. Or consider an interface instead.

Upvotes: 1

G-Man
G-Man

Reputation: 1331

This depends on the classes

If those properties are a property of A then yes, if it's just chance they have the same properties then no.

Basicly the question you need to ask yourself is, will there ever be a class that extends A that doesn't need those properties.

If the answer is no, put them on A,

If the answer is yes, keep them on the sub-classes, or create another abstract class in between those 2 subclasses, having these 2 properties.

Upvotes: 2

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