Junior — Middle
Is it possible to get the result of the launch function execution synchronously?
sobes.tech AI
Answer from AI
The launch function in Kotlin Coroutines starts a new coroutine and immediately returns a Job object. It does not block the current thread and does not return the result of the function it launches. You cannot directly get the execution result from launch in a synchronous manner because launch is intended for starting tasks that do not return a value.
If you need to get the result of an asynchronous operation, you should use async, which returns a Deferred<T>. Then you can call await() to get the result, but await() is a suspension (suspend) and does not block the thread; it only suspends the coroutine.
Example:
val job = launch {
// asynchronous task
}
// job does not contain a result
val deferred = async {
// computation with a result
42
}
runBlocking {
val result = deferred.await() // get the result
println(result) // 42
}
Thus, it is not possible to get the result from launch synchronously; for this, async + await are used.