removeFirst

Removes the first element from this mutable list and returns that removed element, or throws NoSuchElementException if this list is empty.

@IgnorableReturnValuefun <T> MutableList<T>.removeFirst(): T(source)
fun main() {
    val numbers = mutableListOf(1, 2, 3)
    val first = numbers.removeFirst()
    println("Removed: $first")          // 1
    println("Remaining list: $numbers") // [2, 3]
}

Source