How to change the flow in which operations on emitted data are performed and where this data is emitted?

Using the emitOn operator to receive data and flowOn to emit data.

flow {
    // Data emission will occur on thread A
    println("Emit data on thread: ${Thread.currentThread().name}")
    emit(1)
}
.flowOn(Dispatchers.IO) // Thread A - Dispatchers.IO
.onEach { value ->
    // Data processing will occur on thread B
    println("Process data on thread: ${Thread.currentThread().name}")
}
.emitOn(Dispatchers.Main) // Thread B - Dispatchers.Main
.collect { value ->
    // Data collection will occur on thread B (determined by emitOn)
    println("Collect data on thread: ${Thread.currentThread().name}")
}

Differences table:

Operator	Effect on data emission thread	Effect on data processing thread
flowOn	Changes the thread where all upstream code in the Flow chain (before flowOn) runs.	Does not directly affect.
emitOn	Does not directly affect.	Changes the thread where all downstream code in the Flow chain (starting from emitOn) runs.