WordPress Get Next Post and Previous Post Link

wordpress-post-next-previous-link.php

            <div class="col-sm-12">
                <div class="theme-pagination">
                    <ul class="list-inline text-center">

                        <?php // if need post next previous 
                            $prev_post  = get_previous_post(); 
                            $id         = $prev_post->ID ;
                            $permalink  = get_permalink( $id );
                        ?>
                        <?php 
                            $next_post = get_next_post();
                            $nid = $next_post->ID ;
                            $permalink = get_permalink($nid);
                        ?>
                        <li class="pull-left"><?php previous_post_link( '%link', __('<i class="fa fa-arrow-left" aria-hidden="true"></i>', 'mywebsite' ) ); ?>
                        </li>

                        <li class="pull-right"><?php next_post_link( '%link', __( '<i class="fa fa-arrow-right"></i>', 'mywebsite' ) ); ?>
                        </li>
                    </ul>
                </div>
            </div>