Will my passcode be removed if I backup and restore my iPhone?

So my dad put a passcode on my iPhone4… I have the phone but it has a passcode… Can I crack the passcode with ios7? Is there anyway?

Or I have a computer synced with the phone… Can I make a backup and restore?
If I do so passcode will be removed? And if yes… Then how can I get the same passcode back?
so that my doesn't know that I used my iPhone!

Or can I unlock the passcode somehow using iTunes?

No possible way of doing that unless you know the password. Try restoring it if you can't do that then put your iphone in recovery mode or dfu mode then you can probably restore it if you don't know how to do that just google it