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
iOSアプリ開発者から見たKotlin
Search
Koichiro Oishi
June 29, 2017
Programming
2
710
iOSアプリ開発者から見たKotlin
2017/06/29
第6回Kotlin勉強会 @ Sansan
Koishi
Koichiro Oishi
June 29, 2017
Tweet
Share
More Decks by Koichiro Oishi
See All by Koichiro Oishi
気がついたら子供が社会人になって 自分と同じモバイルアプリエンジニアになった件 / Parent-Child Engineers
koishi
0
380
アプリのユニットテストについて初歩から考えてみる/ABC UnitTest
koishi
3
850
Kotlin/Swift 有理数クラスのすすめ
koishi
0
1.3k
5分でわかるPassword_Autofill_for_Apps
koishi
0
1.1k
Other Decks in Programming
See All in Programming
Startups on Rails in Past, Present and Future–Irina Nazarova, RailsConf 2025
irinanazarova
0
250
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
2
15k
オンコール⼊⾨〜ページャーが鳴る前に、あなたが備えられること〜 / Before The Pager Rings
yktakaha4
2
990
The Evolution of Enterprise Java with Jakarta EE 11 and Beyond
ivargrimstad
0
260
テストから始めるAgentic Coding 〜Claude Codeと共に行うTDD〜 / Agentic Coding starts with testing
rkaga
15
5.6k
Goで作る、開発・CI環境
sin392
0
260
The Niche of CDK Grant オブジェクトって何者?/the-niche-of-cdk-what-isgrant-object
hassaku63
1
610
Claude Code派?Gemini CLI派? みんなで比較LT会!_20250716
junholee
1
530
フロントエンドのパフォーマンスチューニング
koukimiura
5
2k
「App Intent」よくわからんけどすごい!
rinngo0302
1
100
PHP 8.4の新機能「プロパティフック」から学ぶオブジェクト指向設計とリスコフの置換原則
kentaroutakeda
2
1k
猫と暮らす Google Nest Cam生活🐈 / WebRTC with Google Nest Cam
yutailang0119
0
170
Featured
See All Featured
Writing Fast Ruby
sferik
628
62k
Navigating Team Friction
lara
187
15k
Designing Dashboards & Data Visualisations in Web Apps
destraynor
231
53k
4 Signs Your Business is Dying
shpigford
184
22k
Building Flexible Design Systems
yeseniaperezcruz
328
39k
Making the Leap to Tech Lead
cromwellryan
134
9.4k
Imperfection Machines: The Place of Print at Facebook
scottboms
267
13k
Thoughts on Productivity
jonyablonski
69
4.7k
The World Runs on Bad Software
bkeepers
PRO
70
11k
GraphQLとの向き合い方2022年版
quramy
49
14k
Faster Mobile Websites
deanohume
308
31k
A designer walks into a library…
pauljervisheath
207
24k
Transcript
iOSΞϓϦ։ൃऀ͔Βݟͨ Kotlin 2017/06/29 ୈ6ճKotlinษڧձ ˏ Sansan Koishi Koichiro Oishi, 2017/6/29
1
ࣗݾհ େੴ ߂Ұ γεςϜɾΞφϥΠζגࣜձࣾ iOSΞϓϦ։ൃऀ ΞΧϯτؔ࿈ * @mego_ * koishi
Koichiro Oishi, 2017/6/29 2
ίϯςΩετ iOSΞϓϦΤϯδχΞͰ͢ɻ Objective-CͱSwiftࣝ͋Δ(͋Δఔ) JavaͳΜͱͳͬͯ͘Δɻ Kotlin໊લͱͳΜͱͳ͘Γ্͕ΓΛɻ Koichiro Oishi, 2017/6/29 3
Kotlin͔Θ͍͍ ͱ͍͏͜ͱΛઌͷษڧձͰΓ·ͨ͠ Koichiro Oishi, 2017/6/29 4
ͦͯ͠ SwiftͱࣅͯΔ ͱ͍͏͜ͱᷚͰΓ·ͨ͠ Koichiro Oishi, 2017/6/29 5
ຊͦΜͳϨϕϧͰݟͨ KotlinͱSwiftͷҧ͍Λ ൃද͖ͤͯ͞·͢ɻ Koichiro Oishi, 2017/6/29 6
ࢀߟจݙ Swift ࣮ફೖ ஶऀͷ1ਓɺੴ͞Μ͔ΒαΠ ϯΒ͍·ͨ͠ɻ Koichiro Oishi, 2017/6/29 7
ࢀߟจݙ Kotlin ελʔτϒοΫ ௨শʮ͜ຊʯ ஶऀͷͨΖ͏͞Μ͔ΒαΠϯ Β͍·ͨ͠ɻ Koichiro Oishi, 2017/6/29 8
ࢀߟจݙ ೖ·Ͱͷ Kotlin ॿಡຊ ࢲʹͱͬͯྑͦ͞͏Ͱ͢ ͪ͜ΒΛϕʔεʹSwiftͱൺֱ ͍͖ͯ͠·͢ Koichiro Oishi, 2017/6/29
9
ຊͰ͢ɻ Koichiro Oishi, 2017/6/29 10
ΞδΣϯμ • جຊจ๏(ͬ͘͟Γ) • Null҆શ • ؔ, ΦϒδΣΫτ(γϯάϧτϯ), ίϯύχΦϯΦϒδΣΫτ(static) •
σʔλΫϥε • Extension(֦ுؔɺ֦ுϓϩύςΟ) Koichiro Oishi, 2017/6/29 11
͜ͷ͋ͨΓΛKotlinͱSwift Ͱൺֱͯ͠Έ·͢ Koichiro Oishi, 2017/6/29 12
جຊจ๏ - มͷએݴ1 Kotlin val num : Int = 1
var num2 : Int = 2 Swift let num: Int = 1 var num2: Int = 2 valͱletఆ 1 Kotlinॿಡຊ p.28 Koichiro Oishi, 2017/6/29 13
جຊจ๏ - มͷએݴ Kotlin val num = 1 var num2
= 2 Swift let num = 1 var num2 = 2 ܕͷলུ(ܕਪ) Koichiro Oishi, 2017/6/29 14
جຊจ๏ - whenࣜ2 Kotlin val value = 1 val str
= when(value) { 1-> "one" 2-> "two" else -> "other" } 2 Kotlinॿಡຊ p.30 Koichiro Oishi, 2017/6/29 15
جຊจ๏ - whenࣜ Swift let value = 1 let str
= { switch value { case 1: "one" case 2: "two" default: "other" } } Koichiro Oishi, 2017/6/29 16
Null҆શ - Nullෆڐ༰ܕ3 Kotlin var a: String = "abc" a
= null // => ίϯύΠϧΤϥʔ Swift var a: String = "abc" a = nil // => ίϯύΠϧΤϥʔ 3 Kotlinॿಡຊ p.33 Koichiro Oishi, 2017/6/29 17
Null҆શ - Nullڐ༰ܕ Kotlin var b: String? = "abc" b
= null // => OK Swift var b: String? = "abc" b = nil // => OK Koichiro Oishi, 2017/6/29 18
Null҆શ - Null νΣοΫͱ҆શͳݺͼग़͠ Kotlin Null ෆڐ༰ܕͷࢀর var a: String
= "abc" val l : Int = a.length // => OK Null ڐ༰ܕͷࢀর var b: String? = "abc" val l : Int = b.length // => ίϯύΠϧΤϥʔ Koichiro Oishi, 2017/6/29 19
Null҆શ - Null ڐ༰ܕͷϝιουݺͼग़͠ Kotlin Null ෆڐ༰ܕͷࢀর var b: String?
= "abc" val l : Int = if(b != null) b.length else -1 Null ڐ༰ܕͷࢀর val l : Int? = b?.length Koichiro Oishi, 2017/6/29 20
Null҆શ - Null ڐ༰ܕͷϝιουݺͼग़͠ Swift Null ෆڐ༰ܕͷࢀর var b: String?
= "abc" let l: Int = b?.characters.count ?? -1 Null ڐ༰ܕͷࢀর let l: Int? = b?.characters.count Koichiro Oishi, 2017/6/29 21
Null҆શ - ΤϧϏεԋࢉࢠ Kotlin val l: Int = b?.length ?:
-1 Swift let l: Int = b?.characters.count ?? -1 Koichiro Oishi, 2017/6/29 22
Null҆શ - !!ԋࢉࢠ Kotlin val l: Int = b!!.length b͕Null(nil)ͩͬͨΒ
KotlinͰNullPointerException͕ൃੜ Koichiro Oishi, 2017/6/29 23
Null҆શ - !!ԋࢉࢠ Swift let l: Int = b!.characters.count ڧ੍Ξϯϥοϓ
b͕Null(nil)ͩͬͨΒ SwiftͰΫϥογϡ͠·͢ Koichiro Oishi, 2017/6/29 24
Null҆શ - Swiftͷ߹ if let count = b?.characters.count { print(count)
//ඇoptionalܕ } if letͷϒϩοΫͰNullෆڐ༰ܕ(ඇoptionalܕ) ͱͯ͑͠Δ Koichiro Oishi, 2017/6/29 25
Null҆શ - Swiftͷ߹ guard let count = b?.characters.count else {
return } print(count) //ඇoptionalܕ guardจҎ߱ͰNullෆڐ༰ܕ(ඇoptionalܕ)ͱ͠ ͯ͑Δ Koichiro Oishi, 2017/6/29 26
ؔ4 Kotlin fun add(x: Int, y: Int): Int { return
x + y } Swift func add(x: Int, y: Int) -> Int { return x + y } 4 Kotlinॿಡຊ p.36 Koichiro Oishi, 2017/6/29 27
ΦϒδΣΫτ(γϯάϧτϯ)5 Kotlin ఆٛ object DataProviderManager { fun registerDataProvider(provider: DataProvider) {
// ... } } ݺͼग़͠ DataProviderManager.registerDataProvider(...) 5 Kotlinॿಡຊ p.47 Koichiro Oishi, 2017/6/29 28
ΦϒδΣΫτ(γϯάϧτϯ) Swift ఆٛ class DataProviderManager { static let sharedInstance =
DataProviderManager() private init() { ... } func registerDataProvider(provider: DataProvider) { } } ݺͼग़͠ DataProviderManager.sharedInstance.registerDataProvider(...) Koichiro Oishi, 2017/6/29 29
ίϯύχΦϯΦϒδΣΫτ(static) Kotlin ఆٛ class MyClass { companion object Factory {
fun create(): MyClass = MyClass() } } ݺͼग़͠ val instance = MyClass.create() Koichiro Oishi, 2017/6/29 30
ίϯύχΦϯΦϒδΣΫτ(static) Swift ఆٛ class MyClass { static func create() ->
MyClass { return MyClass() } } ݺͼग़͠ let test = MyClass.create() Koichiro Oishi, 2017/6/29 31
σʔλΫϥε6 Kotlin data class Person(val id: Long, var name: String)
KotlinʹPairTripleͳͲ͋Δ͕ɺ ม໊͚ͭΒΕͳ͍ͬΆ͍ Swift typealias Person = (id: Int, name: String) σʔλΫϥε = શʹSwiftͷλϓϧͰͳ͘ SwiftͷStructͬΆ͋͞Δʁ 6 Kotlinॿಡຊ p.52 Koichiro Oishi, 2017/6/29 32
Extension - ֦ுؔ(Extension Function)7 Kotlin fun String.appendBeer() : String =
"${this}beer!" println("I like".appendBeer()) // => I like beer! Swift extension String { func appendBeer() -> String { return "\(self)beer!" } } print("I like".appendBeer()) 7 Kotlinॿಡຊ p.55 Koichiro Oishi, 2017/6/29 33
Extension - ֦ுϓϩύςΟ(Extension Properties) Kotlin ఆٛ val <T> List<T>.lastIndex: Int
get() = size - 1 ݺͼग़͠ val arr = listOf(1,2,3) println(arr.lastIndex) //=> 2 Koichiro Oishi, 2017/6/29 34
Extension - ֦ுϓϩύςΟ(Extension Properties) Swift ఆٛ extension Array { var
lastIndex: Int { return self.count - 1 } } ݺͼग़͠ let arr = [1,2,3] print(arr.lastIndex) //=> 2 Koichiro Oishi, 2017/6/29 35
ࠓճ͜͜·ͰͰ͕͢ɺ ͜Ε͔ΒKotlin͍͖ͬͯ·͢ ߴ֊ؔɾϥϜμɾΞΫηε੍ݶ͋ͨΓ औΓ্͔͛ͨͬͨͷͰ͕͢ϘϦϡʔϜతʹ… Koichiro Oishi, 2017/6/29 36
SwiftΛ͋·Γ͝ଘͳ͍ํɺ ͍͔͕Ͱͨ͠Ͱ͠ΐ͏͔ Koichiro Oishi, 2017/6/29 37
Swift ͔Θ͍͍ͷͰ? ͱݴͬͯΈ͔ͨͬͨͷͰ͢ Koichiro Oishi, 2017/6/29 38
࠷ޙʹ Kotlinͷ͕͜͜ྑ͍ ͱ͔ڭ͍͑ͯͩ͘͞ʂ Koichiro Oishi, 2017/6/29 39
ͪͳΈʹ ͜ͷαΠτͰKotlinͱSwiftͷҧ ͍͕·ͱ·ͬͯ·͢Ͷɻ Swift is like Kotlin http://nilhcem.com/swift-is- like-kotlin/ Koichiro
Oishi, 2017/6/29 40
͝੩ௌ͋Γ͕ͱ͏͍͟͝·ͨ͠ɻ Koichiro Oishi, 2017/6/29 41