Creating tabs shortcode

user2587741 posted an answer to their question inside the question:

$tabs_divs="";

function tabs_group($atts, $content = null ) {
    global $tabs_divs;

    $tabs_divs="";

    $output="<div id="tab-side-container"><ul";
    $output.='>'.do_shortcode($content).'</ul>';
    $output.= '<div class="panel-container">'.$tabs_divs.'</div>';

    return $output;  
}  


function tab($atts, $content = null) {  
    global $tabs_divs;

    extract(shortcode_atts(array(  
        'id' => '',
        'title' => '', 
    ), $atts));  

    if(empty($id))
        $id = 'side-tab'.rand(100,999);

    $output="
        <li>
            <a href="#".$id.'">'.$title.'</a>
        </li>
    ';

    $tabs_divs.= '<div id="'.$id.'">'.$content.'</div>';

    return $output;
}

add_shortcode('tabs', 'tabs_group');
add_shortcode('tab', 'tab');