Hi guys, hope you are all doing well. I have a que...

# flow

[Djuro]

Hi guys, hope you are all doing well.
I have a question about merge function of Kotlin flows. In the docs here it says that it doesn't preserve the order of elements.
Do you maybe know of some function that merges multiple flows and preserves the order of elements?

[Jason deBono]

Check flatMapConcat
https://kotlinlang.org/api/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.flow/flat-map-concat.html

[Djuro]

I don't understand how can this help me?
I need to merge 4-5 flows into one flow and get its valeus

[Djuro]

does the point mentioned it doesn't preserve the order of elements mean that elements can come in wrong order or something else?
Let's say I combine Flow<Int> and Flow<String>
Let's say Int is emitted and then String is emitted
What I understood is that the `merge`d flow that I collect can first collect String and then Int even though Int was emitted first

[Jason deBono]

Sorry not sure if I understand.
Have a look at this example

fun test() = flow {
        listOf(
            (1..5).asFlow(),
            (6..10).asFlow(),
            (11..15).asFlow(),
            (16..20).asFlow(),
            (21..25).asFlow(),
        ).map { emitAll(it) }
    }

    test().collect { println(it) }

    merge(
        (1..5).asFlow(),
        (6..10).asFlow(),
        (11..15).asFlow(),
        (16..20).asFlow(),
        (21..25).asFlow(),
    ).collect { println("Merge ---- $it") }