display.php

<?php
header('Content-type: application/json');
include_once "dbconnection.php";

$query = "SELECT task FROM toDoList;";
$result = $link -> query($query);

if (!$result) die ("Database access failed");

$data = array();
for ($i = 0; $i < $result->num_rows; ++$i) {
  $row = $result->fetch_array(MYSQLI_NUM);
  array_push($data, $row[0]);
}
header('Content-Type: application/json');
echo json_encode($data);
$link->close();
?>