getJSON.js

async function getJSON(url, callback) {
  try {
    const response = await fetch(url, {
      method: 'GET',
      mode: 'cors',
      headers: {
        'Content-Type': 'application/json'
      }
    });
    const json = await response.json();
    if (callback) callback(json);
  } catch (error) {
    console.error(error);
  }
}

// function getJSON(url, callback) {
//   fetch(url, {
//     // https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#supplying_request_options
//     method: 'GET', // *GET, POST, PUT, DELETE, etc.
//     mode: 'cors', // no-cors, *cors, same-origin
//     headers: {
//       'Content-Type': 'application/json'
//     }
//   })
//     .then(response => response.json())
//     .then(json => callback(json))
//     .catch(error => console.error(error));
// }