Array & object sort

 <?php
 
          $sel = mysqli_query($conn , "SELECT DISTINCT `lat_log` FROM `visitors`");
            $num = mysqli_num_rows($sel);
            $numArr = [];
            if($num){
                while($r = mysqli_fetch_assoc($sel)){
                    $city = $r['lat_log'];
                    $selcount = mysqli_query($conn , "SELECT `id` FROM `visitors` WHERE `lat_log`='$city'");
                    $ncount = mysqli_num_rows($selcount);
                    // $arr = Array($city , $ncount);
                    $arc = ['city'=>$city,'count'=>$ncount];
                    array_push($numArr,$arc);
                }
                usort($numArr,function($object1, $object2){
                    return $object1['count'] < $object2['count'];
                });
                
                foreach(array_slice($numArr , 0,15) as $k=>$v){
                  ?>
                    <a class="btn btn-info"> <?php echo $numArr[$k]['city']==''?'Unknown city':$numArr[$k]['city'];?> : <?php echo $numArr[$k]['count'];?></a>
                    <?php
                }

            }
          
          ?>