SiroDiaz / DataStructures

        }

        $newNode = new Node($data);

        if($this->head === null) {

            $this->head = &$newNode;

            $newNode->next = null;

        } else {

            $temp = $this->head;

            $this->head = &$newNode;

            $newNode->next = &$temp;

        }

        $this->size++;

    }

    protected function insertEnd($data) {

        $newNode = new SinglyLinkedListNode($data);

        if($this->head === null) {

            $this->head = &$newNode;

            $this->current = &$this->head;

        } else {

            $current = $this->head;

            while($current->next !== null) {

                $current = $current->next;

            }

            $current->next = &$newNode;

        }

    }

    /**