Kotlin_functii_compacte

Kotlin_functii_compacte.kt

fun main(args: Array<String>) {
    println(shouldChangeWater("Friday"))

}
fun getDirtySensorReading() = 20
//acum, jos in functia shouldChangeWater inlocuiesc 20-ul cu functia asta, iar cand se va schimba functia asta(valoarea parametrii etc), in functia mare nu mai modific nimic


fun shouldChangeWater(
        day: String,
        temperature: Int = 22,
        dirty: Int = getDirtySensorReading() ) : Boolean  {

    //var1
//    return when {
//        temperature > 30 -> true
//        dirty > 30 -> true
//        day == "Sunday" -> true
//        else -> false
//    }

    //var2
//    val isTooHot = temperature > 30
////    val isDirty = dirty > 30
////    val isSunday = day === "Sunday"
////    return when {
////        isTooHot > 30 -> true
////        dirty > 30 -> true
////        day == "Sunday" -> true
////        else -> false
////    }


    //var3
    fun isTooHot(temperature: Int) :Boolean = temperature > 30
    fun isDirty(dirty: Int): Boolean = dirty > 30
    fun isSunday(day: String): Boolean = day == "Sunday"
    return when {
        isTooHot(temperature) -> true
        isDirty(dirty) -> true
        isSunday(day) -> true
        else -> false
    }

    //O CHESTIE FAINA DACA FOLOSESTI VARIANTA3 ESTE ca in loc de valoare fixa ca  parametru default, poti sa asignezi o functie, who's return value becomes the default parameter
}

//EXPENSIVE FUNCTIONS = reading files, allocating alot of memory, SLOWS DOWN YOUR APP, because default parameters are EVALUATED AT CALLTIME
//ex:
fun makeNewAquarium() = println("Building a new aquarium")
fun aquariumStatusReport(aquarium: Any =makeNewAquarium()) {}
//when called, you can pass in an existing aquarium, BUT IF YOU DON'T, it builds an entirely new aquarium(si dureaza mult asta)