Java pass by reference issue [duplicate]

Answer 1

You problem is that java is pass by VALUE not reference. So you can't write a swap function the way you did.

you could do something like

class CatContainer {
    Cat cat1;
    Cat cat2;

    CatContainer(Cat cat1, Cat cat2) {
       this.cat1 = cat1;
       this.cat2 = cat2;
    }
    ...
}

and then have a method

public static void swapCatsInContainer(container) {
    Cat tmp = container.getCat1();
    container.setCat1(container.getCat2());
    container.setCat2(tmp);
}

something like that. Now in the scope that called swapCatsInContainer cat1 and cat2 are swapped.