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 is here
Search
Iñaki Villar
July 09, 2017
Technology
0
110
Kotlin is here
Intro to Kotlin.
Google IO Extended Cebu
Iñaki Villar
July 09, 2017
Tweet
Share
More Decks by Iñaki Villar
See All by Iñaki Villar
Scaling Android Builds in Pandemic Times
cdsap
1
150
Building Android Projects with kts
cdsap
2
280
The Build Shrugged
cdsap
1
82
State of Testing in Kotlin
cdsap
0
270
Dexs, R8 and 3.3
cdsap
0
370
Deep Dive Work Manager
cdsap
0
350
Advanced Topics Android
cdsap
0
120
Kotlin: Server-Client
cdsap
0
100
Droidcon Dubai : Kotlin - Server - Client
cdsap
0
67
Other Decks in Technology
See All in Technology
Building a cloud native business on open source
lizrice
0
180
生成AI時代のPythonセキュリティとガバナンス
abenben
0
140
頭部ふわふわ浄酔器
uyupun
0
110
スタートアップの現場で実践しているテストマネジメント #jasst_kyushu
makky_tyuyan
0
130
JSConf JPのwebsiteをGatsbyからNext.jsに移行した話 - Next.jsの多言語静的サイトと課題
leko
2
190
ViteとTypeScriptのProject Referencesで 大規模モノレポのUIカタログのリリースサイクルを高速化する
shuta13
3
210
ブラウザのAPIで Nintendo Switch用の特殊なゲーム用コントローラーを体験型コンテンツに / IoTLT @ストラタシス・ジャパン
you
PRO
0
140
20251027_マルチエージェントとは
almondo_event
1
450
激動の時代を爆速リチーミングで乗り越えろ
sansantech
PRO
1
120
ヘンリー会社紹介資料(エンジニア向け) / company deck for engineer
henryofficial
0
400
What's new in OpenShift 4.20
redhatlivestreaming
0
280
AIエージェントによる業務効率化への飽くなき挑戦-AWS上の実開発事例から学んだ効果、現実そしてギャップ-
nasuvitz
5
1.3k
Featured
See All Featured
Imperfection Machines: The Place of Print at Facebook
scottboms
269
13k
Practical Orchestrator
shlominoach
190
11k
Designing for humans not robots
tammielis
254
26k
Design and Strategy: How to Deal with People Who Don’t "Get" Design
morganepeng
132
19k
ピンチをチャンスに:未来をつくるプロダクトロードマップ #pmconf2020
aki_iinuma
127
54k
Intergalactic Javascript Robots from Outer Space
tanoku
272
27k
The Straight Up "How To Draw Better" Workshop
denniskardys
238
140k
Writing Fast Ruby
sferik
630
62k
The Success of Rails: Ensuring Growth for the Next 100 Years
eileencodes
46
7.7k
BBQ
matthewcrist
89
9.9k
GraphQLとの向き合い方2022年版
quramy
49
14k
Unsuck your backbone
ammeep
671
58k
Transcript
Kotlin is here Too much fun
None
None
None
None
None
.java java compiler .class .jar dex
.kt .java java compiler .class .jar dex kotlin compiler
class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) }
class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) }
class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) }
class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) }
override fun onResume() { super.onResume() mAutofillManager?.registerCallback(mAutofillCallback) } override fun onPause()
{ super.onPause() mAutofillManager?.unregisterCallback(mAutofillCallback) }
None
var index = structure.addChildCount(chidrenSize) val context : Context = request.getContext()
Variables
var index = structure.addChildCount(chidrenSize) val context : Context = request.getContext()
Variables
var index = structure.addChildCount(chidrenSize) val context : Context = request.getContext()
Variables
var index = structure.addChildCount(chidrenSize) val context : Context = request.getContext()
Variables var index : Int = structure.addChildCount(chidrenSize)
var textValue : String = "" textValue = "alo" var
index = structure.addChildCount(chidrenSize) val context : Context = request.getContext() Variables
var textValue : String = "" textValue = "alo" var
index = structure.addChildCount(chidrenSize) val context : Context = request.getContext() Variables val textValue : String = "" textValue = "alo"
var textValue : String = "" textValue = "alo" var
index = structure.addChildCount(chidrenSize) val context : Context = request.getContext() Variables val textValue : String = "" textValue = "alo"
class SimpleClass Classes/Objects
class SimpleClass open class SimpleClass Classes/Objects
class SimpleClass open class SimpleClass class SimpleClass : BaseClass() Classes/Objects
class SimpleClass open class SimpleClass class SimpleClass : BaseClass() class
SimpleClass : SimpleInterface Classes/Objects
class SimpleClass open class SimpleClass class SimpleClass : BaseClass() class
SimpleClass : SimpleInterface object SimpleClass Classes/Objects
class SimpleClass(value: String) Classes/Objects
class SimpleClass(value: String) Classes/Objects class Team { val player :
String var goals : Int }
class SimpleClass(value: String) Classes/Objects class Team { val player :
String var goals : Int }
class SimpleClass(value: String) Classes/Objects class Team { val player :
String = “Rivaldo” var goals : Int = 0 }
class SimpleClass(value: String) Classes/Objects val myPlayer = Team(“Rivaldo”,0) class Team(player:
String, goals: Int)
class SimpleClass(value: String) Classes/Objects val myPlayer = Team(“Rivaldo”,0) class Team(player:
String) { var goals: Int = 0 } class Team(player: String, goals: Int)
class SimpleClass(value: String) Classes/Objects val myPlayer = Team(“Rivaldo”,0) class Team(player:
String) { var goals: Int = 0 } val myPlayer = Team("Rivaldo") myPlayer.goals = 3 class Team(player: String, goals: Int)
Classes/Objects var goals: Int = 0 set(value) { if (goals
> 5) { log(“$player has scored multiple goals") field = value } }
Classes/Objects var goals: Int = 0 set(value) { if (goals
> 5) { log(“$player has scored multiple goals") field = value } } val isEmpty get() = this.size == 0
class SimpleClass(value: String){ init { log() } } Classes/Objects
class SimpleClass(value: String){ init { log() } } Classes/Objects class
Button : View { constructor(ctx: Context) : super(ctx) constructor(ctx: Context, attr: AttributeSet) : super(ctx, attr) }
Classes/Objects data class Team (val name : String, val goals
: Int)
Classes/Objects data class Team (val name : String, val goals
: Int) hashCode - toString - equals
Classes/Objects class A { companion object { fun bar() {
println("Companion Object") } } } data class Team (val name : String, val goals : Int) hashCode - toString - equals
Classes/Objects class A { companion object { fun bar() {
println("Companion Object") } } } data class Team (val name : String, val goals : Int) hashCode - toString - equals A.bar()
Smart Casts public void printTypeProperty(Object object) { if (object instanceof
String) { System.out.print(((String) object).isEmpty()); } else if (object instanceof Integer){ System.out.print(((Integer) object).intValue()); } else if (object instanceof Boolean){ System.out.print(((Boolean) object).booleanValue()); } }
fun printTypeProperty(any: Any) { if (any is String) { println(any.length)
} else if (any is Int) { println(any.plus(1)) } else if (any is Boolean) { println(any.not()) } } Smart Casts public void printTypeProperty(Object object) { if (object instanceof String) { System.out.print(((String) object).isEmpty()); } else if (object instanceof Integer){ System.out.print(((Integer) object).intValue()); } else if (object instanceof Boolean){ System.out.print(((Boolean) object).booleanValue()); } }
fun printTypeProperty(any: Any) { if (any is String) { println(any.length)
} else if (any is Int) { println(any.plus(1)) } else if (any is Boolean) { println(any.not()) } } Smart Casts public void printTypeProperty(Object object) { if (object instanceof String) { System.out.print(((String) object).isEmpty()); } else if (object instanceof Integer){ System.out.print(((Integer) object).intValue()); } else if (object instanceof Boolean){ System.out.print(((Boolean) object).booleanValue()); } }
sealed class Expr data class Const(val number: Double) : Expr()
data class Sum(val e1: Expr, val e2: Expr) : Expr() object NotANumber : Expr() Sealed Classes
sealed class Expr data class Const(val number: Double) : Expr()
data class Sum(val e1: Expr, val e2: Expr) : Expr() object NotANumber : Expr() Sealed Classes
sealed class Expr data class Const(val number: Double) : Expr()
data class Sum(val e1: Expr, val e2: Expr) : Expr() object NotANumber : Expr() Sealed Classes
sealed class Expr data class Const(val number: Double) : Expr()
data class Sum(val e1: Expr, val e2: Expr) : Expr() object NotANumber : Expr() fun eval(expr: Expr): Double = when(expr) { is Const -> expr.number is Sum -> eval(expr.e1) + eval(expr.e2) NotANumber -> Double.NaN } Sealed Classes
sealed class Expr data class Const(val number: Double) : Expr()
data class Sum(val e1: Expr, val e2: Expr) : Expr() object NotANumber : Expr() fun eval(expr: Expr): Double = when(expr) { is Const -> expr.number is Sum -> eval(expr.e1) + eval(expr.e2) NotANumber -> Double.NaN } Sealed Classes
sealed class Expr data class Const(val number: Double) : Expr()
data class Sum(val e1: Expr, val e2: Expr) : Expr() object NotANumber : Expr() fun eval(expr: Expr): Double = when(expr) { is Const -> expr.number is Sum -> eval(expr.e1) + eval(expr.e2) NotANumber -> Double.NaN } Sealed Classes
Interfaces class SimpleClass : SimpleInterface
interface SimpleInterface { fun doSomething() } Interfaces class SimpleClass :
SimpleInterface
interface SimpleInterface { fun doSomething() } interface SimpleInterface { fun
doSomething() fun doAnotherThing() = println("default") } Interfaces class SimpleClass : SimpleInterface
int strLen(String s){ return s.length(); } Nullability
fun strLen(s: String) = s.length int strLen(String s){ return s.length();
} Nullability
fun strLen(s: String) = s.length int strLen(String s){ return s.length();
} fun strLen(s: String?) = … Nullability
fun strLen(s: String) = s.length int strLen(String s){ return s.length();
} fun strLen(s: String?) = … fun strLen(s: String?): Int = if (s != null) s.length else 0 Nullability
fun toUpperCase(s: String?): String? Nullability
fun toUpperCase(s: String?): String? fun toUpperCase(s: String?): String? = s?.toUpperCase()
Nullability
fun toUpperCase(s: String?): String? fun toUpperCase(s: String?): String? = s?.toUpperCase()
Nullability
fun toUpperCase(s: String?): String? fun toUpperCase(s: String?): String? = s?.toUpperCase()
fun length(s: String?): Int Nullability
fun toUpperCase(s: String?): String? fun toUpperCase(s: String?): String? = s?.toUpperCase()
fun length(s: String?): Int fun length(s: String?): Int = s?.length ?: 0 Nullability
fun toUpperCase(s: String?): String? fun toUpperCase(s: String?): String? = s?.toUpperCase()
fun length(s: String?): Int fun length(s: String?): Int = s?.length ?: 0 Nullability
fun toUpperCase(s: String?): String? fun toUpperCase(s: String?): String? = s?.toUpperCase()
fun length(s: String?): Int fun length(s: String?): Int = s?.length ?: 0 Nullability
this as? PageObjectKt Nullability
this as? PageObjectKt Nullability email?.let { email -> sendEmailTo()}
fun max(a: Int, b: Int): Int { return if (a
> b) a else b } Functions
fun max(a: Int, b: Int): Int { return if (a
> b) a else b } Functions
fun max(a: Int, b: Int): Int { return if (a
> b) a else b } Functions
fun max(a: Int, b: Int): Int { return if (a
> b) a else b } Functions
fun createPlayer(name: String, lastName: String, nickName: String?, city: String?) {
Functions - Named Arguments
fun createPlayer(name: String, lastName: String, nickName: String?, city: String?) {
createPlayer("Inaki", "Villar", null, null) Functions - Named Arguments
fun createPlayer(name: String, lastName: String, nickName: String?, city: String?) {
createPlayer("Inaki", "Villar", null, null) createPlayer("Inaki", "Villar", nickName = null, city = null) Functions - Named Arguments
fun createPlayer(name: String, lastName: String, nickName: String = “", city:
String = "Cebu") Functions - Default Arguments
fun createPlayer(name: String, lastName: String, nickName: String = “", city:
String = "Cebu") createPlayer("Inaki", "Villar") Functions - Default Arguments createPlayer("Inaki", "Villar", "Nine")
fun lengthIsGreaterThanFive(s : String) = s.length > 5 val va
= "myVeryLongString" val isGreaterThanFive = lengthIsGreaterThanFive(va) Extension Functions
fun lengthIsGreaterThanFive(s : String) = s.length > 5 val va
= "myVeryLongString" val isGreaterThanFive = lengthIsGreaterThanFive(va) Extension Functions fun String.lengthIsGreaterThanFive() = this.length > 5
fun lengthIsGreaterThanFive(s : String) = s.length > 5 val va
= "myVeryLongString" val isGreaterThanFive = lengthIsGreaterThanFive(va) Extension Functions fun String.lengthIsGreaterThanFive() = this.length > 5
fun lengthIsGreaterThanFive(s : String) = s.length > 5 val va
= "myVeryLongString" val isGreaterThanFive = lengthIsGreaterThanFive(va) val va = "myVeryLongString" val isGreaterThanFive = va.lengthIsGreaterThanFive() Extension Functions fun String.lengthIsGreaterThanFive() = this.length > 5
Infix Functions infix fun Int.minus(value: Int) = this - value
Infix Functions infix fun Int.minus(value: Int) = this - value
Infix Functions infix fun Int.minus(value: Int) = this - value
val result = 4 minus 2
Infix Functions infix fun Int.minus(value: Int) = this - value
val result = 4 minus 2
Infix Functions infix fun Int.minus(value: Int) = this - value
val result = 4 minus 2 4.minus(2)
Infix Functions infix fun Int.minus(value: Int) = this - value
val result = 4 minus 2 infix fun String.repeat(times: Int) = { var result = "" for (i in 1..times) { result += this } }
Infix Functions infix fun Int.minus(value: Int) = this - value
val result = 4 minus 2 infix fun String.repeat(times: Int) = { var result = "" for (i in 1..times) { result += this } }
Infix Functions infix fun Int.minus(value: Int) = this - value
val result = 4 minus 2 infix fun String.repeat(times: Int) = { var result = "" for (i in 1..times) { result += this } } val multipleA = "a" repeat 10
Lambdas
buttonSend.setOnClickListener(new View.OnClickListener(){ @Override public void onClick(View v){ send(); } });
Lambdas
buttonSend.setOnClickListener(new View.OnClickListener(){ @Override public void onClick(View v){ send(); } });
buttonSend.setOnClickListener(object :OnClickListener{ override fun onClick(view : View){ send(); } }) Lambdas
buttonSend.setOnClickListener(new View.OnClickListener(){ @Override public void onClick(View v){ send(); } });
buttonSend.setOnClickListener(object :OnClickListener{ override fun onClick(view : View){ send(); } }) buttonSend.setOnClickListener(View.OnClickListener { view : View -> doSomething() }) Lambdas
{ x : Int, y: Int -> x + y
} Lambdas
{ x : Int, y: Int -> x + y
} Lambdas
{ x : Int, y: Int -> x + y
} Lambdas
data class Team (val name : String, val goals :
Int) val myLeague = listOf(Team("Sakuvic", 12), Team("Rivaldo",10)) Lambdas
data class Team (val name : String, val goals :
Int) val myLeague = listOf(Team("Sakuvic", 12), Team("Rivaldo",10)) myLeague.maxBy({ p: Team -> p.goals }) Lambdas
data class Team (val name : String, val goals :
Int) val myLeague = listOf(Team("Sakuvic", 12), Team("Rivaldo",10)) myLeague.maxBy({ p: Team -> p.goals }) myLeague.maxBy { p: Team -> p.goals } Lambdas
myLeague.maxBy { it.goals } data class Team (val name :
String, val goals : Int) val myLeague = listOf(Team("Sakuvic", 12), Team("Rivaldo",10)) myLeague.maxBy({ p: Team -> p.goals }) myLeague.maxBy { p: Team -> p.goals } Lambdas
None
private val mOnNavigationItemSelectedListener = BottomNavigationView.OnNavigationItemSelectedListener { item -> when (item.itemId)
{ R.id.navigation_home -> { message.setText(R.string.title_home) return@OnNavigationItemSelectedListener true } R.id.navigation_dashboard -> { message.setText(R.string.title_dashboard) return@OnNavigationItemSelectedListener true } R.id.navigation_notifications -> { message.setText(R.string.title_notifications) return@OnNavigationItemSelectedListener true } } false Future is here
Much more Type System Delegation High Order Functions & FP
Operator Generics DSL
None
[email protected]
@inyaki_mwc Thanks