Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Kotlinを使って思った10のコト fukuoka.kt #1
Search
chocomelonchan
July 05, 2017
Programming
0
570
Kotlinを使って思った10のコト fukuoka.kt #1
chocomelonchan
July 05, 2017
Tweet
Share
More Decks by chocomelonchan
See All by chocomelonchan
アプリを最速でリリースした話 #pixiv Night 4
chocomelonchan
4
4.5k
iOSとAndroidで共通のc++のコードを使いたいけど厳しかった話
chocomelonchan
0
1.7k
droidkaigi
chocomelonchan
6
24k
potatotips16
chocomelonchan
3
3k
誰も話たがらない話をしたい 翻訳リソース編
chocomelonchan
2
840
Other Decks in Programming
See All in Programming
MCPを使ってイベントソーシングのAIコーディングを効率化する / Streamlining Event Sourcing AI Coding with MCP
tomohisa
0
170
猫と暮らす Google Nest Cam生活🐈 / WebRTC with Google Nest Cam
yutailang0119
0
170
レトロゲームから学ぶ通信技術の歴史
kimkim0106
0
110
Startups on Rails in Past, Present and Future–Irina Nazarova, RailsConf 2025
irinanazarova
0
240
AI時代の『改訂新版 良いコード/悪いコードで学ぶ設計入門』 / ai-good-code-bad-code
minodriven
23
9.6k
What's new in AppKit on macOS 26
1024jp
0
150
#QiitaBash MCPのセキュリティ
ryosukedtomita
1
1.5k
型で語るカタ
irof
0
700
脱Riverpod?fqueryで考える、TanStack Queryライクなアーキテクチャの可能性
ostk0069
0
500
AI Agent 時代のソフトウェア開発を支える AWS Cloud Development Kit (CDK)
konokenj
6
800
Python型ヒント完全ガイド 初心者でも分かる、現代的で実践的な使い方
mickey_kubo
1
240
状態遷移図を書こう / Sequence Chart vs State Diagram
orgachem
PRO
2
200
Featured
See All Featured
RailsConf 2023
tenderlove
30
1.1k
Build The Right Thing And Hit Your Dates
maggiecrowley
37
2.8k
A Modern Web Designer's Workflow
chriscoyier
695
190k
VelocityConf: Rendering Performance Case Studies
addyosmani
332
24k
Java REST API Framework Comparison - PWX 2021
mraible
31
8.7k
ピンチをチャンスに:未来をつくるプロダクトロードマップ #pmconf2020
aki_iinuma
126
53k
Music & Morning Musume
bryan
46
6.7k
Building a Scalable Design System with Sketch
lauravandoore
462
33k
The Pragmatic Product Professional
lauravandoore
35
6.7k
The World Runs on Bad Software
bkeepers
PRO
70
11k
10 Git Anti Patterns You Should be Aware of
lemiorhan
PRO
656
60k
Sharpening the Axe: The Primacy of Toolmaking
bcantrill
44
2.4k
Transcript
KotlinΛͬͯࢥͬͨ10ͷίτ ࡾࢁ խن (chocomelon) 2017/0705 fukuoka.kt #1
ࣗݾհ ࡾࢁ խن (chocomelon) ωΠςΟϒΞϓϦΛओʹ୲ 2013ϐΫγϒೖࣾ Kotlinྺ 3िؒ
ฐࣾͷKotlin࠾༻ঢ়گ
pixivʢJavaʣ
pixiv ίϛοΫʢJava & Kotlinʣ
pixiv SketchʢJavaɺKotlinʹ͍ͨ͠ʣ
PawooʢJavaɺKotlinʹ͍ͨ͠ʣ
ԬͰ৽ن։ൃதͷΞϓϦ => Kotlin
ԬͰ৽ن։ൃதͷΞϓϦ ɾKotlin ɾAndroid Architecture Components ɹɾViewModel, LiveData, Room ɾDataBinding ɾRxJava/Android
KotlinΛͬͯࢥ͏10ͷίτ
1. Extension͕͢Β͍͠ fun ImageView.setImageUrl(imageUrl: String?) { if (imageUrl == null
|| !URLUtil.isValidUrl(imageUrl)) { return } Glide.with(context).load(imageUrl).into(this) }
2. ؔܕ࠷ߴ͔Α arrayOf(1, 2, 3, 4, 5) // 1, 2,
3, 4, 5 .filter { it % 2 == 0 } // 2, 4 .map {it * 2 } // 4, 8 .sum() // 12
3. σϑΥϧτҾ/͕ศར fun hoge(fugaString: String, fooInt: Int = 0, barBoolean:
= true) { // Do something } val fuga: Int = optionalVal1 ?: 5
4. when͕εϚʔτ viewModel?.getDataSourceState()?.observe(this, Observer { when (it) { DataSourceState.SUCCESS ->
infoView.setType(InfoView.Type.HIDE) DataSourceState.LOADING -> infoView.setType(InfoView.Type.LOADING) DataSourceState.EMPTY_DATA -> infoView.setType(InfoView.Type.NOTFOUND) DataSourceState.ERROR -> infoView.setType( InfoView.Type.ERROR, View.OnClickListener { reload() }) } })
5. SmartCast͕ྑ͍ fun hoge(optionalVal1: String?, optionalVal2: String?) { if (optionalVal1
!= null && optionalVal2 != null) { val hoge = optionalVal1 + optionalVal2 // Do something } } if (object is Person) { print(object.name) }
6. είʔϓ͕ؔศར class HogeActivity: AppCompatActivity() { companion object { val
BUNDLE_KEY_HOGE_INT = "HOGE_INT" fun createIntent(context: Context, hogeInt: Int): Intent = Intent(context, HogeActivity::class.java).apply { putExtra(BUNDLE_KEY_HOGE_INT, hogeInt) } } }
7. let let ͕Ϝζ͍ optionalVal1?.let { optionalVal1 -> optionalVal2?.let {
optionalVal2 -> // Do something } }
7. let let ͕Ϝζ͍ if (optionalVal1 != null || optionalVal2
!= null) { return } // Do something
7. let let ͕Ϝζ͍ optionalVal1 ?: optionalVal2 ?: return //
Do something
7. let let ͕ຊʹϜζ͍ inline fun <S, T, R> let(s:
S?, t: T?, block: (s: S?, t: T?) -> R) { if (s != null && t != null) { block(s, t) } } let(optionalVal1, optionalVal2) { optionalVal1, optionalVal2 -> // Do something }
8. Gson͍ͬͯΔ߹ҙ✋ ɾNonNullͷobjectʹNull͕ೖͬͯ͘Δ ɾύʔε࣌Θ͔Β࣮ͣߦ࣌ʹࢮ͵ ɾmoshi͓͏ https://github.com/square/moshi
9. AndroidΤϯδχΞ͕Δؾ ɾؓࢄͱͯͨ͠Slack͕Kotlinͷॻ͖ํٞ ɹͰΓ্͕Δ ɾࢼߦࡨޡָ͕͍͠ ɾ͙͢͡ΊΒΕΔ => Ұ෦Kotlinʹม͑ͯྑ͍͠ɺ ɹ ࣗಈมͦͦ͜͜༗ೳ
10. iOSͷΤϯδχΞ͕Δؾ ɾʮKotlinͩͬͨΒྑ͍Ͱ͢Αʯ ɾʮSwiftͱࣅͯΔ͡ΌΜʯ ɾʮָͦ͠͏ʢখฒʣʯ
ԬΦϑΟεͰΤϯδχΞืूத ڵຯ͕͋Δํ·ͣϥϯνͰ͠·͠ΐ͏ʂ https://www.wantedly.com/projects/90433