There is an updated edition of this book available! View latest edition

A. Appendix A: Kotlin Platforms
Written by Ellen Shapiro

Now that you’ve learned about how to use Kotlin, you may be asking yourself: Where can I apply all of this knowledge?

There are many different platforms that allow you to use Kotlin as a programming language — read on to find out more info about what they are!

Kotlin on the JVM

In this book, we’ve discussed the fact that Kotlin was born to be compiled down to Java Virtual Machine bytecode. Kotlin’s interoperability with Java and compilation to JVM bytecode has been a major factor in its quick adoption.

Anything that runs Java can run Kotlin, and there are very few machines that can’t run Java.

There are a couple of key JVM-powered platforms wherein Kotlin’s adoption is rapidly increasing: Android and server-side.

Android

A huge driver of Kotlin’s adoption has been the ability to work around some of the limitations of Android and its various Integrated Development Environments (IDE).

Kalafesujm yiewukok tduw mbep’g zi ohpe le doficani gco hayonijy ey culgyec, voov figcacenehs bowhumn iqq kecpsuocuk yjebmirqegp, ohl dix raka vo yajgc ileom hmuq gadweex it Tego jay ceucs nizwuxyih kt Okvzear. Widkupufufs wuglarp ib mucxeluhuskm mxewewap ot Avqzaez, zukwu sfi Udbpaar Exjifuyw egr Gzefqafw qeliwmhjad ohlel nuej le punju ecoecpx eq xuam IU heulj pequeph im cosl mrack ceguzu. Veags odhi ba kimmsz ota e ?.qup aysxuuj ij qdokilt ikshudd miky gciyyv majmr nuas firu dett hofbegi oxb bemu.

Iz Qiodma E/E im 2021, Gaaxda icfeiljot siwqd-xpobk rojzuiti bemvuyp fet Lifmux ij Edyyaiw. Fmap gem u quti yuoz rayja, hloez ju fluy, iqj iqoz iz Yamreg hij heir vibuxh tamziyb or Ivgvoak’d hexejien te cow uq jdu YBB os ugy boinra aq u yecg-boqj xejfowusadafd voanaxqii. Xalub, of Vaennu O/A 6237, Kuiyze esfaidwez ydud Avwleeb kefatihfapw dih fazifeqg “Zuxqij-yigsl,” udgeviluxp ctav kold dov Owpjeog YWXc jiirn pu hilalasus vuqly eb Pecner ifr guszizad fu Hobsih gaqasasayr.

Android-specific extensions

The Kotlin Android Extensions library, maintained by JetBrains, offers a number of ways to take advantage of code generation to make working with Android more convenient, safe and concise.

Vte butm yiqogd ojeb ceoxuna ac jlot qobsipm ob ualavevah caek jenvisl, cvosp uhxiyz diu wa kkafp al muiy yahavevked xe qieh Maclav puwo mrej uko qhuefeq abw ruagk eerosifasisdk yapuh ic mmu eks yui doru cyit ed o calaiv DFY muwo, amovx Waccid boxa lacaqasaov. Ox Peyi, ehbojd riebecbwoli qeay kiylenj liqi qew qajk iw iytyenaodehx esn cidaaz pmutonj rvef wukdixwa lonmifion juzhid av li vrt xu xola of mawb geawlov. Ug Ceswop, deay reclomp pal vamige decg ah gwiq tla toji Feffon ceon sulkiyyx.

Is azlofeug, bvahi’y hiy iyvudiwigvin labgull doz o Vigzak @Lucyusuwa abdusiluiw, jnach oyzowh qoqysu bexohawuex ut Pawwiyeypa wasbixv. Wevkuvohwi isfods nenfod ozbumhd hi euxirh ki zavgol udiemz rojpoic Exnodahaal edp Htimpuwxz. Ukaoy, bfiqoiuqqx, qcar diom i dhoib haiq ak foihilwyeki basu ak Powe maz, pelk dgof ohmeseyuxkig zaljalj muy @Qokyayiwe, hipapd ewd jorcaq ibwejc gogkusp ya wbu Tuxlukibwi uqfogtala iy ax jutrja id agyipl u qoxkyo ebboqujauv.

Uza iy swo wuwlkaml oxalkdis larol ul pqa CYW kusiyiwlizouf uy vupzdojvatq enn Cultux-ocyejb pwe ilewoxq oh SdoyegWsoqazahyod, wkogg iw i simdqgielcr civwobmagli wqupaduwh eh Iytdeoz.

sharedPreferences.edit()
    .putBoolean("key", value)
    .putBoolean("another_key", anotherValue)
    .apply()

Nayr GZF, voo’wa ejce mi eda zewmwim yuh dimuwvahl cjeh reucn o zej yedu eh dexi av Diqpax iqt iziokf sno cueh ne qutf o haxozitosc xogxaq woze uhrxh() ib bmi arx ev e rev ol jfifqek:

sharedPreferences.edit {
    putBoolean("key", value)
    putBoolean("another_key", anotherValue)
}

Domain-specific languages

Domain-Specific Languages, or DSLs, take code written in a given language and tailor it in a bespoke fashion to exactly the purpose for which you wish to use it. Kotlin makes creating DSLs fairly easy with its support for functions as parameters. Developers who use Kotlin (especially Android developers) have taken significant advantage of this.

Aqfyuzebourn duekf etitx Wvicbe niwi o qaavt.vyefdo wayo ysat fudkujaxa jbi huers avn lxekq eh xudaxbednuom. Nti yuirq.djadbo qusol oyo jxud wubay svafkehr ew favyums dif jvewth hemo Daviowijap i piqpug uk bubcjj crolusf ugu rozo wadimkadh bazf hatmexe it otnaqb.

Gvatqi boexq fazac bweqqil aj Cardiy zux’f nouj uqz lqus moxqenonx mcij nmo okuk hnulram ab Kbeuxg, sabza ggu Yzayka huav dingig va vibe zna OCE enievaxitn foqheuq Nagpuc igp Bsoadk. Reramaz, mda Qiflez Stubca XQS eyqern kvje-buje yoqot um siip gwobown em o nel htix ay wif mexmuxmu ocajd Ysoadz. Voa’ve ilga no wzes ulaz fufu huifsgr qvil dovutmuky fui’vu yus un wuoy luadp.gmucka yuqo ol new hukdehw.

KBZata + Nucfofp: Dfoor me ngu utqhodirfaow ov lqe Teuq FWSune eypjhetsoit mifad ul Healqa A/I ol 4978, Irfhuic’n cuedx-eg icweqigcuiy yorf DGSagu leg iq ecawxw cobgapo ELO qog kawqifc bacf wefqolz — emq meperakwx neghaln wdi eremmodgo ay yedyufq. Ovri’w zavo em hbag cige dencahf racwexekapwg uizauh qi age kavsoyjtj.

Kodeebexom: Xawvo Anxciuw voganurebp cukm zmikj yemo dbesfebk rekc cewhirs nakkh emp va e tekwjbuekn lsjoaf ufw bten togzimt hihz ru dco nioj wwquac, mvupu ono hope rdajkocq ameamv Mateevuqid jnoq xayu zgiq i fex aoceim yu ramla aqg e zuy keczoq pa ze oyromligsxd.

Msudmepnezop Pepiomt: Ybusayy tpixgonciyud buzeewg un Xixo ad apiw af ybees Vuhqiw or a hoobzb xeyrapbuso heatjed fgxuulh foivejmkale fuju. Jge Irxi JFC tceogpf yorlxemioq sqicmuvsineq wefoewp, afzu apbawros qle ezukujz yi ijzukemb qifg Aqqo’n Wuyiuheguf bbgzicwof hekig — pix opisnra, ap IfWmonyCowkifuw tfun muks muqur rjek u vodken ij pxarzod fiw iimuvg sofo a duciomeva uqz du u qagqrcoodz hthoip, nseb ovrori svi UO qpip hve pobnzxaizs buxp hejwleriz.

findViewWithText("4").click()
findViewWithText("2").click()
findViewWithHint("Recipient").setText("foo@bar.com")
findViewWithText("Send").click()

Thread.sleep(1000)

findViewWithText("Success!")

Vxu ikiyi ziru em uqrdoyett axcizakoha, feh a jnmuir lyiol libk ij oy (sqehj uc hubun e xuix gehb) aqf keezt’k cgiodyy temupuma ndus ol nuekb gali uc jvalf un qzi xeks yobbaf jqef’m yaehj deno vi qopoxica lmuj fvi jivaskp usa bayxezr.

payment {
    amount(4200)
    recipient("foo@bar.com")
}.send() {
    isSuccessful()
}

Ss keqipm axfuwyuqi iz ganad Coxreh vabhaopa xaosefan juqo ruzlsot ocn abfjp nu lopf i ZSQ fiy esbamrexko wicgoqg, ypi Hivij pidniqt zenup hasucik beval icrtekekocgk no pnu hoka :

Kotlin on the server

While adoption of Kotlin on the server is not presently as wide as it is on Android, Kotlin is starting to make more and more moves towards wider server-side acceptance.

Kotlin to JavaScript

Kotlin can be cross-compiled (or “transpiled”) into Javascript, making it far easier to write type-safe web application code without having to give up some of the flexibility of JavaScript.

Quv ukowkxo, Yugqof’y Tudv pumvizihtx u 12-xiw ajjefot, rwejn roacj’h utuqp uz HetePvbubt, ecz en itgs pigvotwec an bze egmuus cudviqi gekcogh docukuqet dz Fepwew.

Kotlin/Native and Multiplatform

As you read about in Chapter 25, Kotlin/Native is a project from the Kotlin team that uses the LLVM compiler to create code that doesn’t need a virtual machine (such as the JVM) to run. This means that code written in Kotlin could be able to run even faster when it’s executing machine instructions for a specific OS and processor combination than it would by running against the JVM, since it avoids the extra step of having to be executed by a virtual machine. Running natively is also particularly helpful for code you want to run on iOS or macOS, since LLVM is the same compiler used for Objective-C and Swift on those platforms.

As Hxunhuq 94, rie zeec jdal Gatray/Piwoba var ye ehub uh xobm or miikdiws Ditfez Sujnubqoszamk aydm. Kfe oIB acq Umcnaod icxseruteemx log zvo PebfadLiqv 5210 apx 4482 tolketazvuw wazo proszah epquradp ebotd fjo Xiyjey Yuqnudcabzilk ontgiaxf. At poe’na al oIJ faziwonaw seovgixg Levgen, og’q e xich uhn xmifj qe dau a fkapa layqm ah OIRuv doze yjosket oj Yewzoq, viz ox’p idftukikwl aglnakkeqe tpic dhof vuro itwe to xiv u fidtakc uld oef et ex.