Kotlin for Swift Developers - try! Swift Tokyo, March 2018

Video:
https://www.youtube.com/watch?v=JK2s6n80Sl8

Kotlin is a new language born on the JVM that's gained a ton of popularity with Android developers. Learn about its similarities and differences with swift, and a bit about where it's going in the future (though it's not quiiiiite there yet).

Transcript

1. KOTLIN FOR SWIFT DEVELOPERS (SWIFT εЀυϘί΄͵Η΄KOTLIN) TRY! SWIFT | TOKYO, JAPAN | MARCH 2018 @DESIGNATEDNERD | BAKKENBAECK.COM | JUSTHUM.COM
2. HEY, @d_date THANK YOU FOR THE TRANSLATION! (෭๜承΅扖ͭΔͱ
3. !"
11. ✨ " ☕ $ ✨
13. WHAT IS KOTLIN ? ( KOTLIN ᥺承͹ͼ֜ Ҙ)
18. WHY SHOULD I CARE? ( ΀Ͳᐺ΅䶲΁ͯΡ΄͡?)
21. A CONSTANT STRING
22. SWIFT let greeting = "Hello World"
23. SWIFT let greeting = "Hello World" KOTLIN val greeting = "Hello World"
24. AN OPTIONAL INTEGER VARIABLE
25. SWIFT var something: Int?
26. SWIFT var something: Int? KOTLIN var something: Int?
27. ☠ NullPointerException ☠
28. !"
29. GENERICS AND FUNCTIONS AS PARAMETERS ( Ϟ϶ϮЄό;ͭͼֵ͞Ρ樛හ)
30. SWIFT func useFunction<T, U>(on item: T, function: (T) -> U) -> U { return function(item) } func insertExclamationPoint(in string: String) -> String { return string .components(separatedBy: " ") .joined(separator: "! ") } let result = useFunction(on: "try Swift", function: insertExclamationPoint(in:)) // result: "try! Swift"
31. KOTLIN fun <T, U>T.useFunction(action: (T) -> U): U { return action(this) } fun insertExclamationPoint(in: String) : String { return in.split(" ").joinToString("! ") } val result = "try Kotlin".useFunction { insertExclamationPoint(it) } // result: "try! Kotlin"
32. map filter reduce
33. map filter reduce*
34. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(0, +) // reduced: 6
35. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(0, +) // ! // reduced: 6
36. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(0) { $0 + $1 } // reduced: 6
37. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(20) { $0 + $1 } // reduced: 26
38. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(20) { $0 + $1 } // reduced: 26 KOTLIN val numbers = arrayOf(1, 2, 3) val reduced = numbers.reduce { total, current -> total + current } // reduced: 6
39. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(20) { $0 + $1 } // reduced: 26 ⬆ KOTLIN val numbers = arrayOf(1, 2, 3) val reduced = numbers.reduce { total, current -> total + current } // reduced: 6
40. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(20) { $0 + $1 } // reduced: 26 KOTLIN val numbers = arrayOf(1, 2, 3) val folded = numbers.fold(20) ⬅ { total, current -> total + current } // folded: 26
41. SWIFT let doubled = [ 1, 2, 3 ].map { $0 * 2 }
42. SWIFT let doubled = [ 1, 2, 3 ].map { $0 * 2 } KOTLIN arrayOf(1, 2, 3).map { it * 2 }
45. SWIFT let doubled = [ 1, 2, 3 ].map { $0 * 2 } KOTLIN arrayOf(1, 2, 3).map { it * 2 }
46. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(20) { $0 + $1 } // reduced: 26
47. $0 $1 $2...$∞
48. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(20) { $0 + $1 } // reduced: 26 KOTLIN val numbers = arrayOf(1, 2, 3) val folded = numbers.fold(20) { total, current -> total + current } // folded: 26 ⬆
50. !"#
52. guard
53. NOW (匍ࣁ) (KOTLIN) optionalThing?.let { it.doSomething() }
54. NOW (匍ࣁ) (WORSE KOTLIN) if (optionalThing != nil) { optionalThing!!.doSomething() }
55. PROPOSED (൉ໜ) (KOTLIN) guard val thing = optionalThing else { return } thing.doSomething()
56. apply
57. NOW (匍ࣁ) (SWIFT) UserDefaults.standard.set(true, forKey: "DefaultOne") UserDefaults.standard.set(false, forKey: "DefaultTwo)
58. NOW (匍ࣁ) (BETTER SWIFT) let defaults = UserDefaults.standard defaults.set(true, forKey: "DefaultOne") defaults.set(false, forKey: "DefaultTwo)
59. PROPOSED (൉ໜ) (SWIFT) UserDefaults.standard.apply { "DefaultOne" = true, "DefaultTwo" = false, }
62. KOTLIN / NATIVE
63. LLVM
64. LLVM
65. LLVM
66. SUPPORTED PLATFORMS ▸ x86-64 (macOS, Linux, Windows) ▸ arm64 (iOS, Android) ▸ arm32 (Android) ▸ arm32 hardfp (Raspberry Pi) ▸ WebAssembly (Web)
69. DOCUMENTATION
70. DOCUMENTATION? ¯\_(ϑ)_/¯
71. KOTLIN: ☕ OR " = #
72. try? kotlin
73. https://try.kotlinlang.org
76. EDU TOOLS PLUGIN FOR INTELLIJ OR ANDROID STUDIO (INTELLIJ Δ͵΅ ANDROID STUDIO አ΄Ϥ϶ναЀ)
79. OBLIGATORY SUMMARY SLIDE (嬝㵗ጱ΀ᥝ夹) ▸
80. OBLIGATORY SUMMARY SLIDE (嬝㵗ጱ΀ᥝ夹) ▸ Make Friends With Android ▸ (Android ;լᜉͥ΀Σ͜)
81. OBLIGATORY SUMMARY SLIDE (嬝㵗ጱ΀ᥝ夹) ▸ Make Friends With Android ▸ (Android ;լᜉͥ΀Σ͜) ▸ Kotlin Native Is Cool But Not Ready For Production ▸ (Kotlin Native΅͡͹̵͚͚ͩ͢ϤϺύ μτϴЀ΁΅ΔͶֵ͞΀͚)
82. try! Kotlin
83. ONE MORE THING
84. ✨ "#$ ✨
85. ͘Π͢;͚ͪͬ͜Δͭ͵! (THANK YOU VERY MUCH!)
86. LINKS! ▸ Kotlin Home & Documentation https://kotlinlang.org ▸ KotlinConf iOS App in Kotlin/Native: https://github.com/JetBrains/ kotlinconf-app/tree/master/ios ▸ The Edu Tools Plugin for IntelliJ or Android Studio https://kotlinlang.org/docs/ tutorials/edu-tools-learner.html
87. MORE LINKS! ▸ Creating an iOS Framework With Kotlin http://viteinfinite.com/2018/02/creating-an-ios- framework-with-kotlin
88. ILLUSTRATION CREDITS ▸ Monica Komperda, Native Code Forever (Hire her! She's awesome!) http://mokomperda.com/design