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name: coroutines-kotlin description: Master Kotlin coroutines with suspend functions, flows, channels, and structured concurrency for building async applications.

Kotlin Coroutines

Master asynchronous programming in Kotlin with coroutines, flows, and structured concurrency.

Core Concepts

Basic Coroutine

Copyfun main() = runBlocking {
    launch {
        delay(1000L)
        println("World!")
    }
    println("Hello")
}

Suspend Functions

Copysuspend fun fetchUser(id: String): User {
    delay(1000) // Simulating network call
    return User(id, "John Doe")
}

fun main() = runBlocking {
    val user = fetchUser("123")
    println(user)
}

Async/Await

Copysuspend fun loadData(): Data = coroutineScope {
    val user = async { fetchUser() }
    val posts = async { fetchPosts() }

    Data(user.await(), posts.await())
}

Flow

Copyfun simpleFlow(): Flow<Int> = flow {
    for (i in 1..3) {
        delay(100)
        emit(i)
    }
}

fun main() = runBlocking {
    simpleFlow().collect { value ->
        println(value)
    }
}

Channels

Copyfun main() = runBlocking {
    val channel = Channel<Int>()

    launch {
        for (x in 1..5) channel.send(x * x)
        channel.close()
    }

    for (y in channel) println(y)
}

Best Practices

1. Use structured concurrency
2. Handle exceptions properly
3. Use flows for streams
4. Leverage coroutine scope
5. Use dispatchers appropriately
6. Avoid GlobalScope
7. Test coroutines properly

Resources

• https://kotlinlang.org/docs/coroutines-overview.html