Linked list implementation in Swift

LinkedList.swift

class Node {
  var value: String
  var next: Node?
 
  init(value: String, next: Node? = nil) {
    self.value = value
    self.next = next
  }
}

var ari = Node(value: "Ari")
var malcolm = Node(value: "Malcolm", next: ari)
var pete = Node(value: "Pete", next: malcolm)
var ricky = Node(value: "Ricky", next: pete)
var sean = Node(value: "Sean", next: ricky)

var calvin = Node(value: "Calvin", next: pete)
ricky.next = calvin

// Print the list
var currentNode: Node? = sean
while (currentNode != nil) {
  print(currentNode?.value ?? "")
  currentNode = currentNode?.next
}

// Reverse the list
currentNode = sean
var nextPrevious: Node?
var previous: Node?

while (currentNode != nil) {
  // get and store the next node to use it later as a previous value
  nextPrevious = currentNode?.next
  // switch the pointer to the next node of the previous value
  currentNode?.next = previous
  // previous stores the value of the current node
  previous = currentNode
  // the current node becomes the former next node (now the previous node)
  currentNode = nextPrevious
}

// Print the list
print("reversed")
currentNode = ari
while (currentNode != nil) {
  print(currentNode?.value ?? "")
  currentNode = currentNode?.next
}