What methods can be used to implement a sequence of task or data execution?

Sequential execution of tasks or data processing can be implemented in several ways in Android:

1. Callback chaining — executing the next task in the callback of the previous one. For example, calling the next method after completing an asynchronous operation.

2. Using Handler and message queues — tasks are placed in a queue and executed in order in a thread.

3. RxJava (Reactive Extensions) — allows describing a sequence of operations using operators like concat, flatMap, which ensures ordered execution.

4. Coroutines — using suspend functions and operators like launch and async, you can write sequential code that runs asynchronously under the hood.

5. ExecutorService with a task queue — you can use a single-threaded executor that guarantees sequential execution of tasks.

Example with Kotlin Coroutines:

suspend fun sequentialTasks() {
    val result1 = task1() // first task
    val result2 = task2(result1) // second task depends on the first
    println("Result: $result2")
}

suspend fun task1(): String {
    delay(1000) // simulate work
    return "Data1"
}

suspend fun task2(input: String): String {
    delay(1000)
    return "Processed $input"
}