JSFiddle - React, Tailwind, and code Playground

JavaScript

var dfdArray = [];

$(function() {
    var dfd = $.Deferred();
    dfdArray.push(dfd);
    setTimeout(function() { alert('another simple handler'); dfd.resolve(); }, 2000);
});


$(function() {
    var dfd = $.Deferred();
    dfdArray.push(dfd);
    setTimeout(function() { alert('first handler'); dfd.resolve(); }, 1200);
});


$(function() { 
    $.when.apply($, dfdArray).done(function() {
      alert('my final handler'); 
    })
 });