How to erase all data of an app on a iPhone?

I'm trying to restart my progress completely in one of my apps, I want none of my previous information on it. Is there a possible way I could do that?

Uninstall the app

Depends on the app. In most cases just deleting the app would be enough, but if the data is stored elsewhere then nothing could be done, like some games with Facebook integration for example.

  • Will syncing my iPhone erase all of my data? My computer had a hard drive problem so they replaced my computer. I know syncing my iPhone (4s if it matters) to the computer will wipe the current music on my phone, which is fine. I just want to know if it will wipe my other data. Such as pictures, apps, things like that. I would just like to know if it does or not before I sync just so I can save my pictures and things to another place.
  • What will erase and sync erase on my iphone? I wanted to connect my iphone to a new computer but it says erase and sync, what will it erase? All of the contents or just music?
  • If you update your iPhone 4S to 6.0.1 through Wi-Fi, does it erase all your data? I have updated to 6.0 before on my laptop in iTunes, but strangely it didn't erase all my data, so I didn't have to back up. I didn't see it automatically back up during the process of updating, so I was wondering if it would erase all my iPhone data if I updated it through Wi-Fi. A few months before, when I updated to 5.1.1 it erased all my data. I'm not sure if Apple did anything to 6.0 that made it not erase my data…
  • If I erase and sync my iPhone 4 in the music library, will it erase my photos? I'm trying to add music to my iPhone 4 and when I go to sync just the music, it says 'erase and sync'. Will it delete my photos? If so, can I right click my iPhone and back it up so if it does delete my photos, I can just back it up?