Learn Spring for Android Application Development

The when { ... } expression

The switch { ... } control flow element is replaced by when { ... }. The when { ... } element of Kotlin is much more flexible than the switch { ... } element in Java, because it can take a value of any type. A branch only has to contain a matched condition.

The following example demonstrates how to use when { ... } as a statement:

fun whenStatement() {    val x = 1    when (x) {        1 -> println("1")        2 -> println("2")        else -> {            println("else")        }    }}

The preceding code snippet contains the else branch, which is optional for a case with a statement. The else branch is invoked if all other branches don't have a matching condition. The else branch is mandatory if you use when { ... } as an expression and the compiler can't be ...