How to erase an iphone 4 completely but keep the apps?

I want to delete everything from my iphone 4 but keep the apps how may i achieve this?

Added (1). Can i use my computer like itunes and back up the apps only?

That isn't possible. You can go to clean history ect in privacy settings.

You can't. It's not possible. HOWEVER, (This will take a while to do) you can factory reset the iPhone, but before you do that, make sure you've synced all of the apps to iTunes. Do the factory reset, then re-sync all of the apps onto the iPhone. Hope this helps ^^

You need to store all your apps in to your Itunes account. Once this has been done you can factory reset your iphone. Now you just need to put the apps back on the phone via Itunes… Not a big deal.

You either would have to remove everything yourself or have everything removed & then reinstall the apps.