How to get Grand Theft Auto iv cheat codes?

To access cheat codes in Grand Theft Auto IV, you can either input them directly using the in-game phone or type them using your controller or keyboard. For the phone, dial specific numbers corresponding to the cheat you want to activate. You can find a list of cheat codes online or in game guides. Additionally, some cheats can be found in the game's pause menu under the "Cheats" section.