Kotlin, The Force Awakens

Introduction to Kotlin language, chapter I

1. Kotlin The Force Awakens @camachoyury
3. Android official support Kotlin
4. What is Kotlin? • JVM • Seems like Java • Object Oriented • Functional • Less code than Java • No need Classes • Null safety
5. No need Classes fun main(args: Array<String>){ println("be the force with you") }
6. Variables y mutability val name: String = "Kylo Ren" var side = "Force" side = "Dark Side" name = "Kylo" //no compile!!!
7. Template String fun activateSable(color: String){ println("${color} Sable activate!!" ) }
8. “If” is so cool! var sable = true; println( if (sable) { "Activate" }else { "Deactivated" })
9. Null Safety // error no compile var clone: String = null //can not be a value of a non-null type String // could be null var clone2: String? = null clone2 = "clone" // I’m sure, clone2 is not null println( clone2!! )
10. Functions Extension functions
11. Functions • No need to be part of a class • “fun” keyword for create a function • Default parameters • Named Parameters • Extension functions
12. Functions in kotlin fun sableActivated(character: Character) :Boolean { character.sable }
13. Default parameters class Character(name: String, sable: Boolean = false ){ val name = name; var sable = sable }
14. Named parameters var kylo = Character( sable = true, name = "Kylo Ren")
15. Extension functions fun Character.showup(){ println(this.name) println( if (this.sable){ "Has sable" }else "No sable" ) }
16. Extension functions fun String.printYourSelf(){ println(this) } "Force be with you".printYourSelf()
17. Infix functions infix fun Character.fight(character: Character){ println("fight beginig ${this.name} and ${character.name} ") } kylo fight rey
18. Clases class Character(name: String, sable:Boolean ){ val name = name; var sable = sable }
19. Herencia open data class Character(var name: String, var sable:Boolean = false ){ } class SecCharacter(name: String) : Character(name){ }
20. Bye bye POJO data class Character(var nombre: String, var sable:Boolean = false ){} //function by default kylo.toString() kylo.hashCode() kylo.equals() //setters and getters by default kylo.name kylo.sable
21. Questions?
22. https://kotlinlang.org https://antonioleiva.com/ Links reference