Foggy day

val intSrc = Observable.just(1, 2, 3) intSrc.subscribe(::println) val strSrc = intSrc.map { value -> value * 10 } strSrc.subscribe(::println) val src = Observable.just("A", "B", "C", "D") src.flatMap { s -> Observable.just(s + 2, s + 3) } src.subscribe(::println) val flatMap = Observable.range(2, 3).flatMap { x -> Observable.range(1, 9).map { y -> String.format("%d*%d=%d", x, y, x * y) } } flatM..

class KotlinPlayGroundActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_kotlin_play_ground) val lists = listOf(1, 2, 3, 4, 5, 6, 7) println("multiplyMap : ${multiplyMap(lists)} ") println("multiplyMapSecond : ${multiplyMapSecond(lists)}") println("multiplyFold : ${multiplyFold(lists)} ") print..