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Usage of Xamarin

Source: statista.com

ViksaaSkool

Usage of Xamarin 

![xamarin_global1](https://i.imgur.com/ln8eCHA.png)

![xamarin_global2](https://i.imgur.com/Jybm6rN.png)

ViksaaSkool

Tweet{"created_at": "datetime.datetime(date_and_timezone)", "id": "id_of_the_tweet", "text": "Text of the tweet", "user": User{"id": "id_of_the_user", "name": "Screen Name", "screen_name": "twitter_handle", "url": "https://twitter.com/link_to_account"}, "url": "https://twitter.com/link_to_tweet"}

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//One very powerful example of Generics might in combination with delegates is creation of SharedPreferences support
//taken from Kotlin for Android Developers by Antonio Leiva

class MyKotlinSharedPreference<T>(val context: Context, val name: String, val default: T) {

  val prefs by lazy {
     context.getSharedPreferences("default", Context.MODE_PRIVATE)
 }

  //operator overloading

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/* With */
//receives an object, and a function that will be executed as an extension function, which means that with can be used
//inside of a function to refere to the object, i.e. do something "with"
inline fun <T, R> with(receiver: T, f: T.() -> R): R = receiver.f()

//example
fun getPersonFromDeveloper(developer: Developer): Person {
    return with(developer) {
        Person(developerName, developerAge)
    }

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//we have class called Delegate that defines how to get and set values 
class Delegate {
    operator fun getValue(thisRef: Any?, property: KProperty<*>): String {
        return "$thisRef, thank you for delegating '${property.name}' to me!"
    }
 
    operator fun setValue(thisRef: Any?, property: KProperty<*>, value: String) {
        println("$value has been assigned to '${property.name}' in $thisRef.")
    }
}

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//

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//A higher-order function is a function that takes functions as parameters, or returns a function. kotlin has the power 
//to pass around functions 

/* Lambdas */
//by definition, lambda expressions are functions that are not declared, but passed immediately as an expression
//surrounded by curly braces and the body goes after ->

//very basic definition
val sum = { x: Int, y: Int -> x + y }