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
100
graphicsLayer
lvla
0
220
BluetoothDevice.getName()に裏切られた話
lvla
0
360
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
2025 年のコーディングエージェントの現在地とエンジニアの仕事の変化について
azukiazusa1
22
11k
Kiroで始めるAI-DLC
kaonash
2
580
TDD 実践ミニトーク
contour_gara
1
290
Zendeskのチケットを Amazon Bedrockで 解析した
ryokosuge
3
290
AIでLINEスタンプを作ってみた
eycjur
1
230
Improving my own Ruby thereafter
sisshiki1969
1
160
Testing Trophyは叫ばない
toms74209200
0
850
Deep Dive into Kotlin Flow
jmatsu
1
310
Swift Updates - Learn Languages 2025
koher
2
470
AIコーディングAgentとの向き合い方
eycjur
0
270
@Environment(\.keyPath)那么好我不允许你们不知道! / atEnvironment keyPath is so good and you should know it!
lovee
0
110
go test -json そして testing.T.Attr / Kyoto.go #63
utgwkk
3
280
Featured
See All Featured
Cheating the UX When There Is Nothing More to Optimize - PixelPioneers
stephaniewalter
285
13k
A Modern Web Designer's Workflow
chriscoyier
696
190k
The Cult of Friendly URLs
andyhume
79
6.6k
Building Flexible Design Systems
yeseniaperezcruz
328
39k
Balancing Empowerment & Direction
lara
3
620
Intergalactic Javascript Robots from Outer Space
tanoku
272
27k
ReactJS: Keep Simple. Everything can be a component!
pedronauck
667
120k
Java REST API Framework Comparison - PWX 2021
mraible
33
8.8k
Dealing with People You Can't Stand - Big Design 2015
cassininazir
367
27k
I Don’t Have Time: Getting Over the Fear to Launch Your Podcast
jcasabona
33
2.4k
Raft: Consensus for Rubyists
vanstee
140
7.1k
Making the Leap to Tech Lead
cromwellryan
135
9.5k
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