Creating Arrays · Arrays in Kotlin | Kotlin

Creating Arrays

arrayOf and Array Constructor

An array holds a fixed number of values of the same type. Its size cannot change after creation.

Example

Create arrays from values, or with a size and a function that computes each element.

fun main() {
    val cities = arrayOf("Delhi", "Mumbai", "Chennai")
    val squares = Array(5) { i -> i * i }
    val empty = arrayOfNulls<String>(3)

    println(cities.contentToString())
    println(squares.contentToString())
    println(empty.contentToString())
    println(cities.size)
}

Output

[Delhi, Mumbai, Chennai]
[0, 1, 4, 9, 16]
[null, null, null]
3

Printing an Array

Printing an array directly, println(cities), shows something like [Ljava.lang.String;@1b6d3586 (type and memory id), not the values. Use contentToString() or joinToString().

Tip: Lists print nicely by default. That is one reason Kotlin code uses List much more often than arrays.