JSFiddle - React, Tailwind, and code Playground

HTML

<span>hifjdskfj</span>
<p>hhhhhhhhhiiiiiii</p>

JavaScript

/*sample 1*/
var def = $.Deferred();

def.done(function(val){
    alert(val);
});
setTimeout(function(){
    def.resolve("sample 1 completed");
}, 3000);

/*sample 2*/
$("span").fadeOut(5000);
$("span").fadeIn(5000);
$("p").fadeOut(12000);
$("p").fadeIn(2000);

$("span").add("p").promise().done(function(){
    alert("sample 2 completed");
});

/*sample 3*/
var a = $("span").fadeOut(5000);
$("span").fadeIn(5000);
var b = $("p").fadeOut(12000);
$("p").fadeIn(2000);

$.when(a,b).done(function(){
 alert("sample 3 completed");

});