Using List

Creating a list in Kotlin

As a first step in creating a list, Kotlin wants you to declare your intent—immutable or mutable. To create an immutable list, use listOf()—immutability is implied, which should also be our preference when there’s a choice. But if you really need to create a mutable list, then use mutableListOf().

The function listOf() returns a reference to an interface kotlin.collections.List<T>. In the following code the reference fruits is of this interface type, specialized to String for the parametric type:

To access an element in the list you may use the traditional get() method, but the index operator [], which routes to the same method, may be used as well.

// lists.kts
println("first's ${fruits[0]}, that's ${fruits.get(0)}") 
  //first's Apple, that's Apple