Simple LinkList Example in Swift.

LinkList.swift

class Node {
    var val:Int = -1
    var prev:Node? = nil
    var next:Node? = nil
    init(inVal:Int){
        val = inVal
    }
}

class LinkList {
    var head:Node? = nil
    var last:Node? = nil
    init() {
        head = Node(inVal:-1)
        last = head
    }
    
    func addNode(inVal:Int) {
        let tmpNode = Node(inVal: inVal)
        last?.next = tmpNode
        last = tmpNode
    }
    
    func printList() {
        var node = head!.next
        var str = ""
        while (node!.next != nil){
            str = "\(str) \(node!.val) ->"
            node = node!.next
        }
        str = "\(str) \(node!.val)"
        print("\(str)")
    }
}


var myList = LinkList()
myList.addNode(100)
myList.addNode(200)
myList.addNode(300)
myList.printList()

myList.head?.val
myList.head!.next!.val
myList.head!.next!.next!.val
myList.head!.next!.next!.next!.val