new iphone syncing with current itunes/music

hi all, my friend just got a 4s she used to have a 3gs. All her music is on the computer in itunes.

Can she just connect the new iphone to the computer and sync all the music like normal?

ive never had an iphone so dont know :/ just dont want all the music to get wiped or somehting . thx

its ok i found out you just plug it in. sync is one way computer to phone