Arrays are collections of items of the same data type with 0-based indexing that are stored at contiguous memory locations.


// Array class instance
arrayOne = arrayOf<Type>(values)
arrayTwo = Array(size) iteratorFunction

// Array of primitive types
arrayThree: TypeArray = typeArrayOf(values)
arrayFour = TypeArray(size) iteratorFunction

Instances of the Array class are created in either of the following ways:

  • The arrayOf() function accepts an optional <Type> and a comma-separated list of values.
  • With the Array() class constructor that accepts a size parameter and an iteratorFunction for populating the array.

Arrays of primitive type values can also be created:

  • In lieu of TypeArray, actual class names (e.g., IntArray) should be used for typing or constructing the new array.
    • The TypeArray() constructor uses a size parameter as well as an iteratorFunction.
  • The typeArrayOf() function uses a list of values to create an array of a certain data type (e.g., intArrayOf()).


The following example uses the Array() class constructor to create and populate a num array. The elements are then printed:

fun main() {
val num = Array(5, {i-> i*1})
for (i in 0..num.size - 1) {
print(" " + num[i])

This prints the following output:

0 1 2 3 4

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