PHP - get data with Ajax

ajax-get-test-data.php

<?php
if(!isset($_SERVER['HTTP_X_REQUESTED_WITH']) ||
  $_SERVER['HTTP_X_REQUESTED_WITH'] !== 'XMLHttpRequest') {
  die(json_encode(array('status' => "Invalid call.")));
}
$value = array(
  array('id' => 0, 'name' => 'taro', 'age' => '25'),
  array('id' => 0, 'name' => 'jiro', 'age' => '20'),
);
header('Content-Type: application/json; charset=UTF-8');
header('X-Content-Type-Options: nosniff');
echo json_encode($value, JSON_HEX_TAG | JSON_HEX_APOS | JSON_HEX_QUOT | JSON_HEX_AMP);