Remember that GTA 5 cheats also disable achievements in the game and that cheats don't work in GTA online.
However, you'll be taking the fun out of a lot of GTA 5's best missions by using cheats. If you intend to progress through the story much faster, then you can use cheat codes.
GTA 5 cheat codes work in single-player mode but remember that using these will more or less break the game. GTA 5 is one of the few games where cheat codes still exist.