asReversed() vs reversed() in Kotlin?

In Kotlin, both reversed and asReversed have their own unique functions.

The Reverse function returns a list with elements in reversed: order.

Reversed Function

Whereas, the asReversed function returns a reversed read-only view of the original List i.e., all changes made in the original list will be reflected in the reversed one.

asReversed Function

The difference between the two are that once the asReversed() function has been used, any changes in the original list will be reflected in the reversed list as well.
But the same doesn’t hold valid or true when the reversed() function is being used. It’s merely used to reverse a list.

Example:

    val list = mutableListOf(0, 1, 2, 3, 4, 5)

    val asReversed = list.asReversed()
    val reversed   = list.reversed()

    println("Original list: $list")
    println("asReversed:    $asReversed")
    println("reversed:      $reversed")

    list[0] = 10

    println("Original list: $list")
    println("asReversed:    $asReversed")
    println("reversed:      $reversed")

Outputs

Original list: [0, 1, 2, 3, 4, 5]
asReversed:    [5, 4, 3, 2, 1, 0]
reversed:      [5, 4, 3, 2, 1, 0]
Original list: [10, 1, 2, 3, 4, 5]
asReversed:    [5, 4, 3, 2, 1, 10]
reversed:      [5, 4, 3, 2, 1, 0]

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