How to Reverse a List in Kotlin

How to Reverse a List in Kotlin ?

Answer

To reverse a list in Kotlin, you can use the built-in reversed() function or manually reverse the list by iterating over it and swapping elements from both ends.

✐ Examples

1 Reverse a List using reversed() Function

In this example,

We have a list named originalList containing elements in the original order.
We use the reversed() function to create a reversed version of the list.

Kotlin Program

fun main() {
    val originalList = listOf(1, 2, 3, 4, 5)
    val reversedList = originalList.reversed()
    println("Reversed list: $reversedList")
}

Output

Reversed list: [5, 4, 3, 2, 1]

2 Manually Reversing the List

In this example,

We have a list named originalList containing elements in the original order.
We iterate over the list using a loop and swap elements from both ends until we reach the middle of the list.

Kotlin Program

fun main() {
    val originalList = mutableListOf(1, 2, 3, 4, 5)
    var start = 0
    var end = originalList.size - 1
    while (start < end) {
        val temp = originalList[start]
        originalList[start] = originalList[end]
        originalList[end] = temp
        start++
        end--
    }
    println("Reversed list: $originalList")
}

Output

Reversed list: [5, 4, 3, 2, 1]

Summary

In this tutorial, we learned How to Reverse a List in Kotlin language with well detailed examples.

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How to Reverse a List in Kotlin

How to Reverse a List in Kotlin ?

Answer

✐ Examples

1 Reverse a List using reversed() Function

Kotlin Program

Output

2 Manually Reversing the List

Kotlin Program

Output

Summary

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