Iphone needs repair. What should I do?

Okay so my iphone is cracked and the screen itself is damaged, since I've been told that Apple no longer repairs the screen itself but instead gives you a new phone. My question is that if my apps and accounts will be deleted or transferred from the old phone to the new one? AND if It does get erased how do I backup the files?
I don't know if this needs more explanation please answer as best you can.

You can back it up, if not when you get the new one you can transfer all your music from iTunes I'm not sure about apps though.

Usually you can transfer your files onto another platform from your itunes account. If not, ask an Apple representative at the Apple store or you can call them from their office.

Repair it

They do replace the phone, yes. And they do not put your content on the phone. If you're worried back up your phone to itunes and you will have to re-download or re-sync your media.itunes store content can be re-downloaded without charge.