Reverse Singly LinkList in Swift

[Question] Reverse Singly Link List using Iterative & Recursion approach.

// Iterative Approach
func reverseList1(_ head: ListNode?) -> ListNode? {
    var prev = head, currentHead = head?.next
    prev?.next = nil
    while currentHead != nil {// At end of linked list it will be nil.
        let next = currentHead!.next
        currentHead!.next = prev
        prev = currentHead
        currentHead = next
    }
    return prev
}
// Recursive  Approach
func reverseList2(_ head: ListNode?) -> ListNode? {
    if head == nil || head?.next == nil {
        return head
    }
    let newHead = reverseList2(head?.next)
    var nextNode = head?.next
    nextNode?.next = head
    head?.next = nil
    return newHead
}