How long does it take apple to fix an iphone?

I have water damage on my IPhone and I was wondering if I took it in to the closest apple store, if they would fix it right then and there or would I have to pick it up days later?

A couple of days usually.

Depending on the time you drop it off at the apple store. It will usually just take a day. If you drop it off when they open, you can expect to get it back the same day.

Depend if they don't have it in stock you have to wait a couple days. If they are repairing your phone you have to wait anywhere from 30mins to couple hours. If they are replacing your phone with a new unit it takes less than 10mins. Apple only replace part on iPhone 5,5c, or 5s. $ and 4s they just give you a new unit.

I actually didn't even know they repair phones. All I ever would do was take my iphone into the apple store and they would give me a new one the same day.

Depends on what may need to be done to it. More than likely it would take a day or 2.