---
title: "didEnter(from:)"
framework: gameplaykit
role: symbol
role_heading: Instance Method
path: "gameplaykit/gkstate/didenter(from:)"
---

# didEnter(from:)

Performs custom actions when a state machine transitions into this state.

## Declaration

```swift
func didEnter(from previousState: GKState?)
```

## Parameters

- `previousState`: The state the state machine transitioned from to enter this state. If the current state is the initial state of the state machine, this parameter’s value is nil.

## Discussion

Discussion Override this method when the actions you want to perform in response to a state change should be associated with the new state, or when those actions depend on which state a state machine was previously in. For example, in a game where each enemy character has Chase, Flee, Dead, and Respawn states, it might make sense to change the character’s visual appearance when in each state. By putting the appearance-changing code in each state, you ensure that the appearance that corresponds to each state is used only when entering that state. Or, in a state machine that governs a game’s user interface, with Menu, Playing, Paused, and GameOver states, the visual effects for starting a game might differ depending on whether one enters the game from the main menu or restarts from a Game Over screen.

## See Also

### Handling State Transitions and Updates

- [update(deltaTime:)](gameplaykit/gkstate/update(deltatime:).md)
- [willExit(to:)](gameplaykit/gkstate/willexit(to:).md)