find, findLast

The find and findLast functions return the first or the last collection element that matches the given predicate. If there are no such elements, these functions return null.

fun main() {

    val words = listOf("Lets", "find", "something", "in", "collection", "somehow")  // 1
    
    val first = words.find { it.startsWith("some") }                                // 2
    val last = words.findLast { it.startsWith("some") }                             // 3
    
    val nothing = words.find { it.contains("nothing") }                             // 4

    println("The first word starting with \"some\" is \"$first\"")
    println("The last word starting with \"some\" is \"$last\"")
    println("The first word containing \"nothing\" is ${nothing?.let { "\"$it\"" } ?: "null"}")
}

1. Defines a collection of words.
2. Looks for the first word starting with "some".
3. Looks for the last word starting with "some".
4. Looks for the first word containing "nothing".