Can you explain what is meant by side effects in Jetpack Compose?

In Jetpack Compose, side effects are operations that affect state outside the composable function or interact with the external world (e.g., API calls, database writes, starting animations, changing states not directly related to the UI).

Compose is a declarative UI framework where composable functions should be pure (without side effects) to ensure predictability and reproducibility of the UI.

To manage side effects in Compose, special APIs are used, such as:

• LaunchedEffect — for launching coroutines when a key changes.
• SideEffect — for performing actions after a successful composition pass.
• DisposableEffect — for starting and cleaning up resources related to the component's lifecycle.

Example of using LaunchedEffect:

@Composable
fun MyComposable(userId: String) {
    LaunchedEffect(userId) {
        // Fetch data from the network when userId changes
        val data = fetchData(userId)
        // update state
    }
}

Thus, side effects in Compose are controlled operations that allow interaction with the external world without violating the principles of declarative UI.