Will battery replacement at Apple Store wipe phone data?

I am planning to get my iPhone battery replaced at Apple Store and I do have iCloud backup.

1. Is the battery replacement a quick service (hours vs days)?
2. It is a pain to wipe the phone before and restore the data again after, will Apple force a wipe when they replace the battery or will all data be intact (assuming no issues with storage).
3. Do we need to give them our unlock code?

Thanks