Examples of how to use 'let' in Kotlin

As a little note to self, here are a few let examples in Kotlin:

fun main(args: Array<String>) {

    fun toUpper(s: String?): String? = s?.toUpperCase()

    toUpper(null)?.let {
        // this will never be run
        println("toUpper(null) is: ${it}")

    toUpper("emily")?.let {
        println("toUpper(emily) is: ${it}")

    // `let` can return a value
    val hello = toUpper("Hannah")?.let {
        "Hello, ${it}"


The output looks like this:

toUpper(emily) is: EMILY

That’s all I have for today, but if you needed to see how to use let in Kotlin I hope it helps.