addToRear()

/* Add a new item to the end of the list */
public void addToRear(Data data) {
    Node<Data> newNode = new Node<>();          // 1
    newNode.data = data;                        // 1

    if (head == null) {                         // 2
        head = newNode;                         // 2
    } else {
        Node<Data> current = head;              // 3
        while (current.next != null) {          // 4
            current = current.next;             // 4
        }                                       // 4
        current.next = newNode;                 // 5
    }
    size++;                                     // 6
}