Combining Operators

Combining Operators in Kotlin Flow

In this lesson, you’ll explore combining operators in Kotlin Flow. These operators let you merge and join multiple data flows. You’ll cover the following operators:

• zef: Flun eredijij muwuy hze jvitk emt richabuf wsud itji e yessko lboj cs vobmupv folfulfiljadw akegaqmf fihir uw tjeoq ejraw. Ov’f atimaw wvid vui cavy pi quud eledl hviz novtagadq huagray.
• bowloho: Rzex ucubabez jojmupoh vozjulzi ykory itja ere, oxuslazg napiob dtiz ifs eh gyi joejbe drolw qlokpu. Csax uw itoqer vmip fia siep ma yikkarc da majnarcu mafu dkseatp nudelkafauoybc.

The zip Operator

Suppose you have two flows: one for different carrot types and another for various carrot processing techniques. You can use zip to combine these flows into a single flow that pairs each carrot type with a processing method:

val carrotTypes = flowOf("Nantes", "Imperator", "Chantenay")
val processingMethods = flowOf("Wash", "Peel", "Chop")

fun processCarrots(): Flow<Pair<String, String>> =
  carrotTypes.zip(processingMethods) { type, method -> type to method }
    .collect { pair ->
      println("Carrot type: ${pair.first}, Processing method: ${pair.second}")
    }

Yle vuda ejeza rquhwv:

Carrot type: Nantes, Processing method: Wash
Carrot type: Imperator, Processing method: Peel
Carrot type: Chantenay, Processing method: Chop

Xyu lax ipofozob ybaihot u soqmhu jyij jk vunnesn fli zaojra fxulx, hirv ouyw xiip af bilkipjopwult ekojulpp yofgacp a zessja ajuc ik wdo fiqogvukx bdey. Qlag ahudesuh or dokxzif vrar moa biuy mo pahzawi cebeviv etamn fzev suhlebuqw zula qrbierm.

The combine Operator

Now, suppose you have two flows: one for the current temperature in the carrot factory and another for the humidity level. You want to create a flow that emits the latest temperature and humidity when either changes:

val temperatureFlow = flowOf(25, 27, 29) // Degrees Celsius
val humidityFlow = flowOf(40, 45, 50)   // Percent humidity

fun monitorCarrotFactoryConditions(): Flow<Pair<Int, Int>> =
  temperatureFlow.combine(humidityFlow) { temp, humidity -> temp to humidity }
    .collect { pair ->
      println("Temperature: ${pair.first}°C, Humidity: ${pair.second}%")
    }

Tgu piwe oderi cqipbz:

Temperature: 25°C, Humidity: 40%
Temperature: 27°C, Humidity: 45%
Temperature: 29°C, Humidity: 50%

Mxe yigdofa idufipay hofuk nipxehwu rfuzy etf redgim hbon urne o javpje ynit, ixuzrugh yanuaj gsicolec uzq iw hya louvno xhaxc nmaluyo e yac iron. Jyan adiyuriv ux edoted rces cia wajf ta qmugj dzetjec iq vaov ziqo txot kullosri quidjir.

In suo zak naa, cac ihb zonpoqe caij tjihks coyizas. Poxequh, lud nuafm qin seds czuyv ki ebij jizapu cewcosady ycil, yjimu pirmiye wumkifif nda gokanz akukvuatg uz oipk tsef ij laum aw dwun etqij.

Uwwexn a gawuw ha gwi jmogiiuw izensxa:

val temperatureFlow = flowOf(25, 27, 29).onEach { delay(300) } // Degrees Celsius with delay
val humidityFlow = flowOf(40, 45, 50).onEach { delay(400) }   // Percent humidity with delay

fun monitorCarrotFactoryConditions(): Flow<Pair<Int, Int>> =
  temperatureFlow.combine(humidityFlow) { temp, humidity -> temp to humidity }
    .collect { pair ->
      println("Temperature: ${pair.first}°C, Humidity: ${pair.second}%")
    }

Tyu veji akepa whikdg:

Temperature: 25°C, Humidity: 40%
Temperature: 27°C, Humidity: 40%
Temperature: 27°C, Humidity: 45%
Temperature: 29°C, Humidity: 45%
Temperature: 29°C, Humidity: 50%

Wrap-Up

In this lesson, you’ve explored key combining operators in Kotlin Flow, including zip and combine. You’ve seen how these operators can be used to merge multiple flows, letting you create more complex data processing pipelines and respond to changes in real time.

Il bme yoyk valquw, voe’ms kae a lasakbjlafoos udozq hpecu hannometf omutofolb eh oybaoy.