What would happen if I keep my iPhone 4 charging all night? Would it cause any damage to my phone or battery?
I have had iPhones since Day one and every night I Sync and Charge all night. What did you think would happen...? It's a MAC!
It would be fine, it wont hurt the battery or the IPhone.
After a while it's not good for it I wouldnt recommend doing it very often
If I were you I would not keep my iPhone plugged in all night. Later in your iPhone's lifetime you might begin to have battery issues. You are better off charging a few times during the day and not allowing the batter to go completely dead.
I went you to Apple Store yesterday I asked the rep the same question and he said it will be fine.
I do it all the time
I do it all night and it's fine