Programming Kotlin

Using List

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:

collections/lists.kts

val fruits: List<String> = listOf("Apple", "Banana", "Grape")
println(fruits) //[Apple, Banana, Grape]

To access an element in the list you may use the traditional get() method, but the index operator [] ...