IT SHARED IN KOTLIN KEISHIN YOKOMAKU

ςΩετ KOTLIN ▸ JetBrains ͕։ൃͨ͠ JVM Ͱಈ͘ݴޠ ▸ Ϟμϯͳจ๏ΛऔΓೖΕͨ Better Java ͳݴޠ ▸ 1.0.0 ͕͍ͭ࠷ۙϦϦʔε͞Εͨ

ςΩετ MODERN SYNTAX IN KOTLIN ▸ Ϧετͷૢ࡞ ▸ filter, map, let ͳͲศརͳϝιου͕͋Δ ▸ Java8 ͷ Stream API Έ͍ͨͳ΋ͷ͕ඪ४౥ࡌ fun main(args: Array) { listOf(1, 2, 3) .filter {n -> n < 3} .let {n -> print(n)} } => [1, 2]

ςΩετ MODERN SYNTAX IN KOTLIN ▸ σʔλΫϥε ▸ ϓϩύςΟΛอ࣋͢ΔΫϥε(=Entity)༻ͷಛผͳએݴ ▸ Getter/Setter ΍ equals/hashCodeɺtoString ΛΑ͠ͳʹ ΍ͬͯ͘ΕΔͷͰࣗ෼Ͱॻ͔ͳ͍͍ͯ͘ data class Person(val name: String, val age: Int) val eq = Person(“Hirata”, 29) .equals(Person(“Jita”, 30)) print(eq) => false

ςΩετ KEYWORD ▸ it ▸ 1 ͭͷҾ਺Λ࣋ͭϒϩοΫͷҾ਺Λ it ͰࢀরͰ͖Δ fun main(args: Array) { listOf(1, 2, 3) .filter {n -> n < 3} .let {n -> print(n)} }

ςΩετ KEYWORD ▸ it ▸ 1 ͭͷҾ਺Λ࣋ͭϒϩοΫͷҾ਺Λ it ͰࢀরͰ͖Δ fun main(args: Array) { listOf(1, 2, 3) .filter {it < 3} .let {print(it)} }

ςΩετ data class Article (val name: String, val shared: Boolean);

ςΩετ data class Article (val name: String, val shared: Boolean); fun main(args: Array) { listOf(Article(“Think Social?”, true), Article(“Facebook”, true), Article(“mixi”, false)) .filter {it.shared} .let {print(it)} }

ςΩετ data class Article (val name: String, val shared: Boolean); fun main(args: Array) { listOf(Article(“Think Social?”, true), Article(“Facebook”, true), Article(“mixi”, false)) .filter {it.shared} .let {print(it)} } => [Article(name=“Think Social?”, shared=true), Article(name=“Facebook”, shared=true)]

IT SHARED