Kotlin and why should you care about it ?

ME

🇹🇭 Born and bred in BKK, THAILAND

🗼 Living in Tokyo for 3.5 years

Advanced issue found

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📱 Mobile and Open source, Kotlin, Swift C++ 💖

ME

github.com/kittinunf

@kittinunf

Ok, Kotlin

Statically typed language for JVM, Android, and the browser

Created by Jetbrains back in 2010

Open sourced, hit 1.0 released in Feb 2016

Seamlessly integrate with IntelliJ platform - also Android Studio

Kotlin ... why?

Inherent Java language restrictions

- Cannot add methods on platform types

- Problem with null

Advanced issue found

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- Mutability is everywhere

- Force to evolve everything around Object

Kotlin - Crash course

Null safety	Enum class	Immutability
Type Inference	Properties & Fields	Data class
Lambda	Extension Functions	High order functions
Type-safe builder	Collection APIs	Kotlin-Java Interoperable

Null Safety

Enum / Sealed class

Mutable/Immutable

Type reference

Properties & Fields

Data class

Lambda

Extension Function

High-order function

Type-safe Builder

Rich Collection API


    val a = (1..10) + (1..10)
    
    a.all { it > 0 }                            a.subtract(5..10)
    
    a.any { it % 2 == 0 }                       a.sortedWith { .... } 

    a.average()                                 a.sum()

    a.distinct()                                a.take(3)

    a.dropWhile { it < 5 }                      a.toList()/a.toArrayList()

    a.filterNot { it > 0 }                      a.toSet()/a.toHashSet()

    a.groupBy { if (it < 3) "<3" else ">3" }    a.toCollection(MyAwesomeCollection())
    
    a.intersect(2..4)                           a.toLinkList()

    a.joinToString("-")                         a.toMap({ if (it % 2 == 0) "even" else "odd" }, 
                                                        { it.toString })

    a.max(), a.min()                            a.map { it to it.toString() }.unzip()

    a.none { it < 1 }                           a.withIndex()

    a.reversed()                                a.union(10..20)

    a.sortedBy { it % 3 == 0 }                  a.zip(10..20)