JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://jquery-json.googlecode.com/files/jquery.json-2.2.min.js"></script>

JavaScript

function doAjax(xx){
    var xdata = {json: $.toJSON({name: xx}),
                delay: 1};
   return $.ajax({
        url:"/echo/json/",
        data:xdata,
        type:"POST"
    });
    
}

var carr = [doAjax('a'),doAjax('b'),doAjax('c'),doAjax('d')]
var result = [];

$.when( carr )
    .done(function(data){
        console.log(data);
        $.each(data, function(ix,val){
            console.log(val.name);
        });
    });