Kotlin: Convert an Array to a List

1. Introduction

Working with arrays and lists is common in programming. Though they might seem similar, they serve different purposes and have different operations. There might be occasions when we need to switch from one data structure to the other. In this post, we'll explore how to convert an Array into a List in Kotlin.

2. Program Overview

The steps in our program include:

1. Initiating an array of numbers.

2. Converting an array into a list.

3. Displaying the initial array and its list counterpart for validation.

3. Code Program

fun main() {
    // Step 1: Initiate an array of numbers
    val arrayOfNumbers = arrayOf(1, 2, 3, 4, 5)

    // Step 2: Transmute the array into a list
    val listOfNumbers: List<Int> = arrayOfNumbers.toList()

    // Step 3: Display the initial array and its list counterpart
    println("Array: ${arrayOfNumbers.joinToString()}")
    println("List: $listOfNumbers")


Array: 1, 2, 3, 4, 5
List: [1, 2, 3, 4, 5]

4. Step By Step Explanation

1. Initiating an Array:

  • The program initializes an array named arrayOfNumbers with a series of integer values.

2. Array to List Transformation:

  • Kotlin's array type comes equipped with the toList() extension function. This handy function swiftly turns any array into a list. Using this method on arrayOfNumbers, we obtain the listOfNumbers.

3. Result Demonstration:

  • To print an array, we utilize the joinToString() function to produce a human-readable format. This is because, by default, printing an array would not give a clear string representation of its elements.
  • For the list, the default toString() function is sufficient for a clear output, so we just print it directly.

The ability to switch between arrays and lists in Kotlin is made smooth and efficient by its well-designed standard library.