How to get back the Wi-Fi password?

My dad forgot the Wi-Fi password, and I can't get into it on my phone. He said the only way to get the password is to reset the system? (I don't know what system).So is that the only way? Any other ways besides hacking? And we only have Mac computers, and i have an iPhone 4S.

If you have a Wi-Fi router then look underneath for a sticker. Look for something that says: Etherenet MAC: (a lot of numbers and letters). Then look at the numbers and letters. The password may be the last 7 or 8 numbers and letters.

The only way to get your password is to reset your Wi-Fi and reinstall it
you can use backtrack but it's more complicated than reset your Wi-Fi