Linear Search Algorithm in Kotlin

1. Introduction

In this tutorial, we will learn how to implement a simple Linear Search Algorithm using Kotlin programming language.

Linear Search, also known as Sequential Search, is a simple search algorithm where each element in the dataset is checked sequentially until a match is found or the whole set has been searched. It is straightforward and works by comparing each element with the element to be searched, one by one.

2. Implementation Steps

1. Start from the leftmost element of the array and compare it with the key element.

2. If the element matches with the key, return the index.

3. Move to the next element and repeat step 2.

4. If the end of the array is reached without finding the key, return -1 indicating the element is not present.

3. Implementation in Kotlin Programming

fun linearSearch(arr: List<Int>, key: Int): Int {
    for (index in arr.indices) {
        if (arr[index] == key) return index
    return -1
fun main() {
    val numbers = listOf(64, 34, 25, 12, 22, 11, 90)
    val key = 22
    println("List: $numbers")
    val result = linearSearch(numbers, key)
    if (result == -1) {
        println("$key is not present in the list.")
    } else {
        println("$key is present at index $result.")


List: [64, 34, 25, 12, 22, 11, 90]
22 is present at index 4.


1. Linear Search starts by comparing the key element with the first element of the list.

2. If they are not the same, it continues comparing with the next element.

3. This process is repeated until the key is found or the end of the list is reached.

4. If the key element matches an element in the list, the index of that element is returned. Otherwise, -1 is returned indicating the element was not found.