#Intro
Kotlin is a new programming language for the JVM. It produces Java bytecode, supports Android and generates JavaScript. The latest version of the language is Kotlin M5.3
Kotlin project website is at kotlin.jetbrains.org.
All the codes here can be copied and run on Kotlin online editor.
Let's get started.
This is a quick guide to Kotlin programming language. The previous part of this guide is here
#Object Oriented
fun main(args : Array<String>) {
class local (val x : Int)
val y = local(10)
println("${y.x}")
#Control Structures
##If statement
Kotlin if statement should look familiar with other language
fun main(args : Array<String>) {
val total = 10
| // A couple of inlined utility functions: the first is just a syntax convenience, the second lets us use | |
| // Kotlin's string interpolation efficiently: the message is never calculated/concatenated together unless | |
| // logging at that level is enabled. | |
| inline fun <reified T : Any> loggerFor(): org.slf4j.Logger = LoggerFactory.getLogger(T::class.java) | |
| inline fun org.slf4j.Logger.trace(msg: () -> String) { | |
| if (isTraceEnabled) trace(msg()) | |
| } | |
| /** | |
| * A Java logging formatter that writes more compact output than the default. |
| open class A { | |
| } | |
| abstract class Adapter<T : A> { | |
| abstract fun create(): T | |
| abstract fun itemCount(): Int | |
| open fun bind(a: T) { | |
| } | |
| } |
| package actors | |
| import com.google.common.util.concurrent.ListenableFuture | |
| import com.google.common.util.concurrent.SettableFuture | |
| import com.google.common.util.concurrent.MoreExecutors | |
| import java.util.concurrent.Executors | |
| import java.util.ArrayList | |
| import java.util.concurrent.LinkedBlockingQueue | |
| import com.google.common.util.concurrent.ListeningExecutorService | |
| import java.util.concurrent.ThreadFactory |
| fun get(url: String, headers: Headers = Headers()): Observable<Response> { | |
| //return getWithExplicitClass(url, headers)!! | |
| //return getWithAnonymousClass(url, headers)!! | |
| //return getWithInlineUsingObsoleteSubscribeFunc(url, headers)!! | |
| return getWithFailingInlineFunction(url, headers)!! | |
| } | |
| fun getWithFailingInlineFunction(url: String, headers: Headers = Headers()) : Observable<Response>? { | |
| // This fails. Looks like a bug in Kotlin: http://youtrack.jetbrains.com/issue/KT-4598 |
| apply plugin: 'com.android.application' | |
| apply plugin: 'kotlin-android' | |
| apply plugin: 'me.tatarka.retrolambda' | |
| buildscript { | |
| ext.kotlin_version = '1.0.0-beta-4584' | |
| ext.android_support_lib_version = '23.1.1' | |
| ext.retrolambda_version = '3.2.4' | |
| repositories { | |
| jcenter() |
| import rx.Observable | |
| import rx.Observer | |
| import rx.Subscriber | |
| import rx.Subscription | |
| import rx.functions.Action0 | |
| import rx.functions.Action1 | |
| fun <T> Observable<T>.uiSubscribe(schedulers: Schedulers, subscriber: Subscriber<in T>): Subscription { | |
| return subscribeOn(schedulers.io) | |
| .observeOn(schedulers.mainThread) |
| package pl.kpob.utils.extensions | |
| import android.app.Activity | |
| import android.content.Context | |
| import android.graphics.Color | |
| import android.support.v4.content.ContextCompat | |
| import android.view.WindowManager | |
| import flow.Flow | |
| import org.jetbrains.anko.AlertDialogBuilder | |
| import pl.sisms.gminformix.utils.extensions.supportsLollipop |