SiroDiaz / DataStructures

     *

     * @return mixed the data stored in the node.

     */

    private function deleteEnd() {

        $prev = $this->head;

        $current = $this->head;

        while($current !== $this->tail) {

            $prev = $current;

            $current = $current->next;

        }

        $temp = $current;

        $prev->next = &$this->head;

        $this->tail = &$prev;

        $current = null;

        $this->size--;

        return $temp->data;

    }

    /**

     * Removes all nodes of the list. It removes from the beginning.

     *

     * @return mixed the data stored in the node.

     */

    private function deleteEnd() {

        $prev = $this->head;

        $current = $this->head;

        while($current !== $this->tail) {

            $prev = $current;

            $current = $current->next;

        }

        $temp = $current;

        $prev->next = &$this->head;

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

        $this->tail = &$prev;

        $current = null;

        $this->size--;

        return $temp->data;

    }

    /**

     * Converts/exports the list content into array type.