![Swift
var shoppingList = ["catfish", "water",
"tulips", "blue paint"]
shoppingList[1] = "bottle of water"
Kotlin
val shoppingList = arrayOf("catfish", "water",
"tulips", "blue paint")
shoppingList[1] = "bottle of water"
Swift is like Kotlin:
Arrays](https://image.slidesharecdn.com/dscmuethellotokotlin-201025183754/85/Hello-to-Kotlin-42-320.jpg)
Hello to Kotlin
- 3. life begins at the end of your COMFORT ZONE-Neale Donald Walsch-
- 5. Kick Start With Kotlin Arbaz Pirwani @arbazpirwani
- 8. 2016 2017 2018 2019 2020 Kotlin Timeline
- 9. 2016 2017 2018 2019 2020 1.0 Kotlin Timeline
- 10. 2016 2017 2018 2019 2020 1.0 Google I/O: Kotlin Officially supported language for Android Kotlin Timeline
- 11. 2016 2017 2018 2019 2020 1.0 Google I/O: Kotlin Officially supported language for Android Google I/O: Android goes Kotlin-first Kotlin Timeline
- 12. 2016 2017 2018 2019 2020 1.0 Google I/O: Kotlin Officially supported language for Android Google I/O: Android goes Kotlin-first Coroutines Preferred Kotlin Timeline
- 13. Kotlin Timeline 2016 2017 2018 2019 2020 1.0 Google I/O: Kotlin Officially supported language for Android Google I/O: Android goes Kotlin-first You are here Coroutines Preferred
- 14. WHY KOTLIN?
- 15. - Google Preferred Language - Statistically typed - Type Inference - Developed by Jetbrains - Concise - 100% interoperable with Java - Null Safety - And many more.
- 16. I don’t like Kotlin
- 17. I Love Kotlin
- 18. Java vs Kotlin
- 19. Java to Kotlin
- 23. Question Of The Day WHY DO KOTLIN AND JAVA PROGRAMMERS WEAR GLASSES? BECAUSE THEY DON’T SEE SHARP.BECAUSE THEY DON’T SEE SHARP.
- 26. Why Kotlin? Expressiveness Safety Interoperability Structured concurrency
- 27. class MainActivity : AppCompatActivity () { override fun onCreate(savedInstanceState: Bundle?) { ... fab.setOnClickListener { view -> Snackbar.make(view, "Hello ${name.capitalize()}", Snackbar.LENGTH_LONG).show() } fab.backgroundTintList = backgroundTintList } } Why Kotlin?
- 28. class MainActivity : AppCompatActivity () { override fun onCreate(savedInstanceState: Bundle?) { ... fab.setOnClickListener { view -> Snackbar.make(view, "Hello ${name.capitalize()}", Snackbar.LENGTH_LONG).show() } fab.backgroundTintList = backgroundTintList } } Nullability in the type system Why Kotlin?
- 29. class MainActivity : AppCompatActivity () { override fun onCreate(savedInstanceState: Bundle?) { ... fab.setOnClickListener { view -> Snackbar.make(view, "Hello ${name.capitalize()}", Snackbar.LENGTH_LONG).show() } fab.backgroundTintList = backgroundTintList } } Nullability in the type system Lambdas Why Kotlin?
- 30. class MainActivity : AppCompatActivity () { override fun onCreate(savedInstanceState: Bundle?) { ... fab.setOnClickListener { view -> Snackbar.make(view, "Hello ${name.capitalize()}", Snackbar.LENGTH_LONG).show() } fab.backgroundTintList = backgroundTintList } } Nullability in the type system Lambdas Extension functions Why Kotlin?
- 31. class MainActivity : AppCompatActivity () { override fun onCreate(savedInstanceState: Bundle?) { ... fab.setOnClickListener { view -> Snackbar.make(view, "Hello ${name.capitalize()}", Snackbar.LENGTH_LONG).show() } fab.backgroundTintList = backgroundTintList } } Nullability in the type system Lambdas Template expressions Extension functions Why Kotlin?
- 32. class MainActivity : AppCompatActivity () { override fun onCreate(savedInstanceState: Bundle?) { ... fab.setOnClickListener { view -> Snackbar.make(view, "Hello ${name.capitalize()}", Snackbar.LENGTH_LONG).show() } fab.backgroundTintList = backgroundTintList } } Nullability in the type system Lambdas Template expressions Extension functions Property access syntax for getters and setters Why Kotlin?
- 33. Kotlin Uptake 60% of Pro Android Developers use Kotlin 70% of Top 1000 Apps contain Kotlin code Source: Google internal data, May 2020
- 34. ● Data Classes ● Extension Methods ● Elvis Operator ● Properties ● Default Parameters ● Type Aliases ● Named Parameters ● Spread Operator ● Auto Casts ● Covariance ● Null Safety ● Operator Overloading ● Type Inference ● DSL Support ● Type-Safe Builders ● Coroutines ● String Interpolation ● Ranges ● Map Array Syntax ● Inline Functions ● Sealed Classes ● Delegation ● Destructuring ● KDoc Coroutine s
- 35. Coroutines ● Coroutines are like very light-weight threads ● Asynchronous programming made easy ● No callbacks ● No complex functionality
- 36. VS
- 37. Kotlin & Swift ● The syntax of Swift doesn’t just resemble that of Kotlin: in small chunks of code there can be up to 77% string similarity. ● At the very least, it should be noted that while Swift appeared in 2013, Kotlin originated back in 2011. Hence, even though comparing Kotlin to Swift (in this exact order) can be convenient due to Swift’s earlier introduction to a wide audience, any ‘copycat’ attitudes towards Kotlin aren’t justified.
- 38. Kotlin & Swift ● Available on both mobile-client and back-end server ● Highly performant and statically-typed ● Kotlin also can be used for web front-end via Kotlin.JS
- 39. Swift is like Kotlin: Hello World Swift print("Hello, world!") Kotlin println("Hello, world!")
- 40. Swift var myVariable = 42 myVariable = 50 let myConstant = 42 Kotlin var myVariable = 42 myVariable = 50 val myConstant = 42 Swift is like Kotlin: Variables And Constants
- 41. Swift let explicitDouble: Double = 42 Kotlin val explicitDouble: Double = 42.0 Swift is like Kotlin: Explicit Types
- 42. Swift var shoppingList = ["catfish", "water", "tulips", "blue paint"] shoppingList[1] = "bottle of water" Kotlin val shoppingList = arrayOf("catfish", "water", "tulips", "blue paint") shoppingList[1] = "bottle of water" Swift is like Kotlin: Arrays
- 43. Swift func greet(_ name: String,_ day: String) -> String { return "Hello (name), today is (day)." } greet("Bob", "Tuesday") Kotlin fun greet(name: String, day: String): String { return "Hello $name, today is $day." } greet("Bob", "Tuesday") Swift is like Kotlin: Functions
- 44. Swift class Shape { var numberOfSides = 0 func simpleDescription() -> String { return "A shape with (numberOfSides) sides." } } Kotlin class Shape { var numberOfSides = 0 fun simpleDescription() = "A shape with $numberOfSides sides." } Swift is like Kotlin: Classes
- 45. • Advantages over Java 7 are overwhelming • Java 8 introduced • Lambdas • Null safety (“Optional” class) • Default methods • Streams API • New Date & Time API Java strikes back with Java 8
- 46. • Is more elegant, concise and safe • Has more cool stuff But even with Java 8 Kotlin still...
- 48. • Functions - definition in package or in class • Immutable/mutable variables • No “new” keyword • Type inference • No checked exceptions • No primitive types • No static members Basic syntax and rules More elegant?
- 49. • Primary constructors • No fields, just properties • Bean style classes easy to declare • By default, all classes are final Basic syntax and rules cont’d More elegant?
- 50. • Null reference – Billion dollar mistake • Kotlin is designed in a way that aims to eliminate NPE from our code Null Safety More elegant? Tony Hoare
- 51. • Declaration-site variance • out / in generics modifiers • Supports use-site variance also • No wildcard syntax, out / in used Generics More elegant?
- 52. MORE COOL STUFF
- 53. • Default argument values can be defined • Arguments with default values are optional • No more need for function overloading (almost) • Kotlin classes can have only one constructor • Arguments can be called by name • When passing arguments by name ordering doesn’t matter Default arguments and named arguments
- 54. • Simpler “is it in range” check • Can be used for any type that implements Comparable • “both ends“ included • “..” operator is translated to “rangeTo” function • “rangeTo” function is implemented as extension function on Comparable • Numerical ranges can be iterated over • In both directions and in arbitrary steps Ranges
- 55. Ranges
- 56. • Java’s instaceof not very practical • No !instanceof • Meet Kotlin’s "is“ • "is" negation "!is“ • Automatic type cast when “is” evaluates true inside if / when blocks Pattern matching
- 57. AND MANY MORE
- 58. Resources • https://kotlinlang.org/ • https://play.kotlinlang.org/ • http://nilhcem.com/swift-is-like-kotlin/
- 59. FreeCodeCamp.org
- 62. Best Kotlin Learning Resources
- 63. Arbaz Pirwani