JAVA vs KOTLIN Which one to choose and Why? By Deesha Vora (@Deesharv, [email protected]) Co-founder and CPO @SuperWiseSite 

I JAVA Because... Easy Object oriented Platform-independent Portable Distributed Robust 2 

Because I know JAVA... 3 I JAVA Really 

Why new language “Kotlin” ? - Concise yet expressive - Function Types - Kotlin doesn’t have checked exception - Collection filtering like Swift and Java 8 - Lazy Loading feature - Data class - lateinit, Delegates.notNull - Extension functions 4 

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Function types in Kotlin. Function accepting another function. fun max(collection: Collection, less: (T, T) -> Boolean): T? { var max: T? = null for (it in collection) if (max == null || less(max, it)) max = it return max } 6 

Functional collection extensions JoinToString (fun Iterable.joinToString()) Creates a string from all the elements separated using separator and using the given prefixand postfix if supplied. Any (fun Array.any(): Boolean) Returns true if array has at least one element. Associate (fun Iterable.associate( transform: (T) -> Pair): Map) Returns a Map containing key-value pairs provided by transform function applied to elements of the given collection. 7 

lateinit, Delegates.notNull and lazy val movie: String var name: String? = null lateinit var name: String var age: Int by Delegates.notNull() val imm: InputMethodManager by lazy { getSystemService(INPUT_METHOD_SERVICE) as InputMethodManager } 8 

Extension functions fun Activity.hideKeyboard(): Boolean { val view = currentFocus view ? .let { val inputMethodManager = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager return inputMethodManager.hideSoftInputFromWindow(view.windowToken, InputMethodManager.HIDE_NOT_ALWAYS) } return false } 9 

JAVA CODE vs KOTLIN CODE public class User { private String firstName; private String lastName; public String getFirstName() {return firstName;} public void setFirstName(String firstName) {this.firstName = firstName;} public String getLastName() {return lastName;} public void setLastName(String lastName) {this.lastName = lastName;} } 10 class User { var firstName: String? = null var lastName: String? = null } 

40 % cut in the number of lines of code. 11 

The Future, Kotlin/Native - Access to Objective C APIs - Kotline can be used for both iOS and Android - From server back-end to the web or mobile clients - LLVM compiler to generate machine code - (Supports Mac OSx 10+, Ubuntu 14+, iOS arm64, Raspberry Pi ) 12 

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https://goo.gl/2EFxmJ 14 

Should I learn Kotlin from today ? How? If not now, Sooner or later you will have to. It is simple if you know JAVA already. 15 Should I switch my apps to Kotlin? That depends, how old and huge is your app. 6 months to 3 months? consider changing it to kotlin 1 year or older? then wait...You might want to consider interoperability of Kotlin. Or you might not want to do it at all. 

Still confused…? 16 Shoot your queries... Catch me @Deesharv, Email:[email protected]