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頻出表現
Search
Moyuru Aizawa
November 28, 2016
Programming
0
270
Kotlin頻出表現
Kotlinでよくつかう文/式等
TwitterID変えました。@lvla0805 -> @MoyuruAizawa
Moyuru Aizawa
November 28, 2016
Tweet
Share
More Decks by Moyuru Aizawa
See All by Moyuru Aizawa
BLUETOOTH_SCAN and iBeacon
lvla
1
98
graphicsLayer
lvla
0
210
BluetoothDevice.getName()に裏切られた話
lvla
0
350
Jetpack Composeで画像クロップ機能を実装する
lvla
0
1.2k
Jetpack Compose drag gesture and pinch gesture
lvla
1
3.9k
Jetpack Compose Layout API
lvla
1
660
BLEを使ったアプリを継続的に開発するために
lvla
0
1k
RecyclerView.ItemAnimator
lvla
1
320
RecycledViewPool
lvla
1
220
Other Decks in Programming
See All in Programming
GUI操作LLMの最新動向: UI-TARSと関連論文紹介
kfujikawa
0
940
それ CLI フレームワークがなくてもできるよ / Building CLI Tools Without Frameworks
orgachem
PRO
17
3.9k
あなたとJIT, 今すぐアセンブ ル
sisshiki1969
1
670
CLI ツールを Go ライブラリ として再実装する理由 / Why reimplement a CLI tool as a Go library
ktr_0731
3
1.1k
ライブ配信サービスの インフラのジレンマ -マルチクラウドに至ったワケ-
mirrativ
1
230
バイブコーディング × 設計思考
nogu66
0
120
AIに安心して任せるためにTypeScriptで一意な型を作ろう
arfes0e2b3c
0
370
#QiitaBash TDDで(自分の)開発がどう変わったか
ryosukedtomita
1
370
Understanding Ruby Grammar Through Conflicts
yui_knk
1
110
Vibe coding コードレビュー
kinopeee
0
440
Comparing decimals in Swift Testing
417_72ki
0
170
No Install CMS戦略 〜 5年先を見据えたフロントエンド開発を考える / no_install_cms
rdlabo
0
480
Featured
See All Featured
Agile that works and the tools we love
rasmusluckow
329
21k
How To Stay Up To Date on Web Technology
chriscoyier
790
250k
How to Create Impact in a Changing Tech Landscape [PerfNow 2023]
tammyeverts
53
2.9k
A better future with KSS
kneath
239
17k
Evolution of real-time – Irina Nazarova, EuRuKo, 2024
irinanazarova
8
890
実際に使うSQLの書き方 徹底解説 / pgcon21j-tutorial
soudai
PRO
183
54k
Connecting the Dots Between Site Speed, User Experience & Your Business [WebExpo 2025]
tammyeverts
8
460
Scaling GitHub
holman
462
140k
Balancing Empowerment & Direction
lara
2
570
Building Applications with DynamoDB
mza
96
6.6k
The Power of CSS Pseudo Elements
geoffreycrofte
77
5.9k
Typedesign – Prime Four
hannesfritz
42
2.8k
Transcript
,PUMJOසग़දݱ !MWMB
lvla lvla0805 Ѫᖒ๖ .PZVSV"J[BXB -FBEFOHJOFFSPGQBJST%JWFVSFLB *OD FVSFLB,PUMJO&WBOHFMJTU
+BWB,PUMJO3Y+BWB
None
QBJST $PVQMFT NBUDIHSPVQ *"$ OPXIJSJOH
None
NFFUT
WBM
‣ SFBEPOMZ ‣ جຊWBMΛར༻͍ͯ͠Δɻ ‣ ňͦΕWBSͰ͋Δඞཁ͋Δͷ ʼn ‣ ΈΜͳ+BWBॻ࣌͘ʹpOBMΛ͚ͭΔΑ͏ʹͳͬͨ WBM
val readOnliy = 10 readOnliy = 20 // error
/VMMBCMF
‣ /VMMΛڐ༰͢Δܕͱɺ/VMMΛڋ൱͢Δܕ͕໌֬ʹΘ͚ΒΕ͍ͯΔ ‣ OPU/VMMʹOVMMೖͰ͖ͳ͍͠ɺOVMMBCMFΛೖ͢Δ͜ͱग़དྷͳ ͍ ‣ ৗʹ/VMMΛҙࣝͯ͠ίʔσΟϯά͢Δ͜ͱʹͳΔ /VMMBCMF val nullable:
String? = null var notNull: String = null // error notNull: String = nullable // error
4BGF$BMM
‣ /VMMBCMF͕/VMMͷ߹ɺOVMM͕ฦ٫͞ΕΔɻ ‣ /VMMBCMF͕/VMMͰͳ͍߹ɺ͕࣮ؔߦ͞ΕΔϓϩύςΟͷ͕ฦ٫ ͞ΕΔɻ 4BGF$BMM nullablePerson?.toString() nullablePerson?.age
%FMFHBUFE1SPQFSUJFT
‣ ϓϩύςΟͷॳظԽΛҕৡͰ͖Δ ‣ ॳظԽΛԆͰ͖Δ ‣ ϥΠϑαΠΫϧʹґଘ͢ΔͷͰWBMͰॳظԽͰ͖Δ %FMFHBUFE1SPQFSUJFT val view by
bindView(R.id.view) val string by lazy { getString(R.string.foo) }
&YUFOTJPO'VODUJPO
‣ ܧঝ͢Δࣄͳ͘ɺطଘΫϥεʹؔΛՃͰ͖Δɻ &YUFOTJPO'VODUJPO fun Activity.toWeb(uri: Uri) { startActivity( Intent(Intent.ACTION_VIEW, uri)
) } fun Subscription.addTo(subscriptions: CompositeSubscription) { subscriptions(this) }
4JOHMF&YQSFTTJPO'VODUJPO
‣ ؔͷ࣮͕୯Ұࣜͷ߹ɺฦΓͷએݴɺϒϩοΫɺSFUVSOΛলུ Ͱ͖Δɻ 4JOHMF&YQSFTTJPO'VODUJPO @Provide fun provideApplicationContext() = applicationContext
)JHIFS0SEFS'VODUJPO
‣ ؔΛҾʹͱͬͨΓ ‣ ؔΛฦ٫͢Δؔ ‣ +BWB͕ؔϑΝʔετΫϥεΦϒδΣΫτ͡Όͳ͍͔Β͜Ε͕Ͱ͖ ͳ͍ )JHIFS0SEFS'VODUJPO fun foo(
function: (Int)->Unit ) { … } fun bar(): (Int)->String { … }
‣ 7JFXΛҾʹͱΓ6OJU 㲈7PJE Λฦ٫͢ΔؔͱಉͰ 4". public interface OnClickListener { void
onClick(View var1); }
‣ ؔͭͷΠϯλʔϑΣʔεΛҾʹऔΔؔʹɺؔΛͤ·͢ ‣ هड़ྔΊͬͪΌݮΔʜ 4". view.setOnClickListener({ view -> view.visibility =
View.GONE }) view.setOnClickListener { view -> view.visibility = View.GONE } view.setOnClickListener { it.visibility = View.GONE }
MFU
‣ ؔΛ͢ͱɺͦͷؔΛ࣮ߦͯ͘͠ΕΔɻ ‣ 4BGF$BMMͰMFUΛ࣮ߦ͍ͯ͠ΔͷͰɺOVMMͰͳ͍߹ʹͷΈ࣮ߦ͞Ε Δɻ MFU nullable?.let { it.doSomething }
BQQMZ
‣ Ϩγʔό 'PP'SBHNFOU ͷϓϩύςΟؔΛར༻͢ΔؔΛ͢ ‣ ͦΕΒ͕ద༻͞ΕͨϨγʔό͕ฦ٫͞ΕΔɻ BQQMZ FooFragment().apply { arguments
= Bundle().apply { pustString("key", "value") } }
‣ 4JOHMF&YQSFTTJPO'VODUJPOͱΈ߹ΘͤΔͱ͖ͬ͢Γ BQQMZ fun newInstance() = FooFragment().apply { arguments =
Bundle().apply { pustString("key", "value") } }
EFDMBSJOHQSPQFSUJFTBOE JOJUJBMJ[JOHUIFNGSPNQSJNBSZ DPOTUSVDUPS
‣ ϓϩύςΟͷએݴͱॳظԽΛɺϓϥΠϚϦίϯετϥΫλͰߦ͑Δ ‣ ϗϯτָʜ EFDMBSJOHQSPQFSUJFTBOEJOJUJBMJ[JOHUIFNGSPNQSJNBSZDPOTUSVDUPS class Person(val firstName: String, val
lastName: String, var age: Int) { // ... }
%BUB$MBTT
‣ FRVBMT IBTI$PEF UP4USJOH DPQZ ΛίϯύΠϧ࣌ʹੜͯ͠ ͘ΕΔ ‣ Ξοϓσʔτ͞Εͳ͍FRVBMT ͱ͞Α͏ͳΒͰ͖Δɻ
%BUB$MBTT data class Person(val firstName: String, val lastName: String, var age: Int)
OUBSPLOJU
‣ ֦ுؔΛͬͯBTTFSU5IBUΛ͍͍ײ͡ʹͯ͘͠ΕΔ ‣ ͏͜Ε͕ͳ͍ͱςετॻ͚ͳ͍ʜ LOJU @Test fun test() { (1
+ 2).should be 3 // assertThat(1 + 2, `is`(3)) }
TZTZBHJLNPDLJUP
‣ ֦ுؔΛͬͯNPDLJUPΛ͍͍ײ͡ʹͯ͘͠ΕΔɻ ‣ ͜Εͳ͍ͱςετͰ͖ͳ͍ʜ LNPDLJUP var item: Item = mock()
item.length().invoked.thenReturn(10) item.length().should be 10 item.verify().length()
5IBOLZPV