window.setInterval(loadNewPosts, 1000); //load simultaneous choice in 1 second

function loadNewPosts(){
$.ajax({
      type: "GET",
      cache: false,
      dataType: "json",
      url: "latest.php",
      data: "current_id=" + current_id +"&nextType=" + nextType,
      success: function(data) {

        for (var i = 0; i < data['array_x'].length; i++) {
            array_x.push(data['array_x'][i]);
            array_y.push(data['array_y'][i]);
        }

    }
    });
}

$servername = "";
$username = "";
$password = "";
$dbname = "";
$conn = mysqli_connect($servername, $username, $password, $dbname);
// Check connection
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}

$current_id = intval($_GET['current_id']);
$Type = (string)$_GET['nextType'];
$sql = "SELECT * FROM `table` WHERE id > $current_id and Type='".$Type."'";
$result = mysqli_query($conn, $sql);
$array_x= [];
$array_y= [];


if (mysqli_num_rows($result) > 0) {
    // output data of each row
    while($row = mysqli_fetch_assoc($result)) {
        array_push($array_x,$row["X"]);
        array_push($array_y,$row["Y"]);
   }
} else {
    echo "";
}

mysqli_close($conn);

// return the posts as a JSON object
header('Content-Type: application/json');
$data=array(
  'array_x' => $array_x,
  'array_y' => $array_y
);
echo json_encode($data);