Question

So I have this really large method I wrote. If it’s given a stack, it will return a stack. If it’s given a queue, it will return a queue. It uses a lot of recursion, and it accepts a queue/stack and returns that same queue/stack modified accordingly.

I don’t want to copy/paste my method just so I can change the type used inside, so is there any way I can make this generic? As in, it will accept any old collection and play with it? I tried just using Collection, but the trouble with that is it doesn’t have a .remove() I can use with the stack/queue.

Any help would be greatly appreciated.

Thanks.

Answer 1

You could use Collection but then have special case handling just around your remove operations. Of course you’ll have to figure out what to do when you get a collection that’s not one of the two.

if (myCollection instanceof Queue) {
    ((Queue)myCollection).remove();
} else if (myCollection instanceof Stack) {
    ((Stack)myCollection).remove(thingy);
} else {
    // Oops! Now what?
}