husen-hn

const cartItem = [
    {
        title: 'Book1',
        exist: false
    }, {
        title: 'Book2',
        exist: true
    }, {
        title: 'Book3',
        exist: true

husen-hn

Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
  if (message.data['message'] == 'Calling message') {
    showCallNotification(
        3, message.data['chatroomid'], message.data['userName']);
  }

  await Firebase.initializeApp();
}

void main() async {

husen-hn

fun main() {
    val immutableList = listOf(1,2,3,4,5,6,7) //(1) 
    println("Immutable List $immutableList") 
    val mutableList = immutableList.toMutableList() //(2) 
    println("Mutable List $mutableList") 
    mutableList.add(8) //(3) 
    println("Mutable List after add $mutableList") 
    println("Mutable List after add $immutableList") 
}

husen-hn

class MutableObj { 
    var value = "" 
 
    override fun toString(): String { 
        return "MutableObj(value='$value')" 
    } 
} 
 
fun main() { 
    val mutableObj:MutableObj = MutableObj()//(1) 

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val myOtherValue = MyOtherValue("Foo")

myOtherValue.value = "Bar"  // This will not compile because value cannot be reassigned

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class MyOtherValue(default: String) {
   lateinit var value: String
       private set
}

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val mutable = MyValue.Mutable("Foo")
val immutable = MyValue.Immutable("Foo")

mutable.value = "Bar"    // This is fine

immutable.value = "Bar"  // This will not compile because value cannot be reassigned

val mutated = immutable.mutate()
mutated.value = "Bar"    // This is fine

husen-hn

sealed class MyValue(default: String) {

   open val value: String = default

   class Immutable(default: String): MyValue(default) {
       fun mutate(): Mutable = Mutable(value)
   }

   class Mutable(default: String) : MyValue(default) {
       fun immutate(): Immutable = Immutable(value)

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val space = Space()

println(space.all) // result 47

val squares = 30
space.squares = squares * 2

println(space.all) // result 84

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class Space{
   var squares = 24
   var triangles = 23

   val all: Int
       get() {
           return squares + triangles
       }
}