Mastering Kotlin

Type casting

It's possible to cast a variable of one type to another type. If the types are not compatible, an exception is thrown. To perform a type cast in Kotlin, we use the as keyword. We'll explore how to perform a type cast with the following examples:

1. First, we have defined a SettingsProvider interface and an implementing SettingsManager object:

interface SettingsProvider {    fun getSetting(key: String) : String}object SettingsManager : SettingsProvider {    ...    fun printSettings() = map.forEach { println(it) }}

2. In this example, we use as to cast the settingsProvider variable to SettingsManager so we can call a specific method on the variable:

fun main(args: Array<String>) {    val settingsProvider: SettingsProvider = SettingsManager