jquery check local fil echange withou callback code example

Example 1: javascript check if file exists on server

function doesFileExist(urlToFile) {
    var xhr = new XMLHttpRequest();
    xhr.open('HEAD', urlToFile, false);
    xhr.send();
     
    if (xhr.status == "404") {
        return false;
    } else {
        return true;
    }
}

Example 2: loading page for all ajax call in jquery 3.3.1

$(document).ajaxStart(function () {
            $('#ajax-loading-image').css("display", "block");
        });
        $(document).ajaxStop(function () {
            $('#ajax-loading-image').css("display", "none");
        });