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
830
Other Decks in Programming
See All in Programming
なんとなくわかった気になるブロックテーマ入門/contents.nagoya 2025 6.28
chiilog
1
260
たった 1 枚の PHP ファイルで実装する MCP サーバ / MCP Server with Vanilla PHP
okashoi
1
220
What Spring Developers Should Know About Jakarta EE
ivargrimstad
0
380
20250628_非エンジニアがバイブコーディングしてみた
ponponmikankan
0
620
AIプログラマーDevinは PHPerの夢を見るか?
shinyasaita
1
190
システム成長を止めない!本番無停止テーブル移行の全貌
sakawe_ee
1
160
なぜ「共通化」を考え、失敗を繰り返すのか
rinchoku
1
620
Result型で“失敗”を型にするPHPコードの書き方
kajitack
4
560
ふつうの技術スタックでアート作品を作ってみる
akira888
0
310
ソフトウェア品質を数字で捉える技術。事業成長を支えるシステム品質の マネジメント
takuya542
0
600
PHPで始める振る舞い駆動開発(Behaviour-Driven Development)
ohmori_yusuke
2
240
Blazing Fast UI Development with Compose Hot Reload (droidcon New York 2025)
zsmb
1
280
Featured
See All Featured
Fashionably flexible responsive web design (full day workshop)
malarkey
407
66k
How to train your dragon (web standard)
notwaldorf
94
6.1k
Six Lessons from altMBA
skipperchong
28
3.9k
Helping Users Find Their Own Way: Creating Modern Search Experiences
danielanewman
29
2.7k
Improving Core Web Vitals using Speculation Rules API
sergeychernyshev
17
950
ReactJS: Keep Simple. Everything can be a component!
pedronauck
667
120k
Documentation Writing (for coders)
carmenintech
72
4.9k
The Psychology of Web Performance [Beyond Tellerrand 2023]
tammyeverts
48
2.9k
Put a Button on it: Removing Barriers to Going Fast.
kastner
60
3.9k
Done Done
chrislema
184
16k
StorybookのUI Testing Handbookを読んだ
zakiyama
30
5.9k
The Pragmatic Product Professional
lauravandoore
35
6.7k
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