If i switch Wi-Fi and 3g both on always, will it use more iphone battery?

1st option: i usually use Wi-Fi at home and 3g outside home, so if i leave both Wi-Fi and 3g "on", my phone will automatically connect to Wi-Fi at home and 3g outside.

2nd option: switch on ONLY Wi-Fi at home and change every time to 3g while going out.
which option saves your battery? Is it same

Switching on and off saves such little amount of battery it's not worth the trouble.

Your phone handles it automatically. Don't worry about turning it on and off manually. The phone can only be connected one way at a time for data anyway.