Скачать или смотреть Check network status using Javascript

The checkNetworkStatus function is designed to determine the online/offline status of a user's internet connection using JavaScript. Instead of relying on the potentially unreliable navigator.online property, this function takes a more practical approach by attempting to make an actual network request.

The function creates a new XMLHttpRequest object, a standard API in JavaScript for making HTTP requests.
An event listener is set up to handle the readystatechange event, which is triggered each time the state of the request changes.
The function opens a GET request to a specified endpoint (in this case, '"website name").
When the request state becomes XMLHttpRequest.DONE (complete), it checks the HTTP status code:
If the status code is 200, it indicates a successful request, and the function logs "Online."
If the status code is different from 200, it indicates an unsuccessful request, and the function logs "Offline."