Kotlin for Enterprise Applications using Java EE

When clause

when is a pattern matching clause in Kotlin. This helps us to write elegant code when dealing with pattern matching, meaning we can avoid using a lot of if else statements.

Let's write a function that takes an input, the type of which is not known. Any is used to indicate this and a when block is used to handle different patterns.

Consider the code for 10_when.kts:

fun processInput(input: Any) {    when(input) {        10 -> println("It is 10")        98,99 -> println("It is 98 or 99")        in 101 .. 120 -> println("More than 100")        is String -> println("This is ${input} of length ${input.length}")        else -> println("Not known")    }}processInput(10)processInput(98)processInput(99)processInput(102)processInput("hey there")processInput(Thread())

The output ...