JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://code.jquery.com/jquery-2.2.4.min.js"></script>

JavaScript

var notWorks = {
  aa: "string",
  bb: "str"
}

function why() {
  var thisWorks = notWorks;
  $.get("/echo/json").then(function() {
    printVal(notWorks);
    printVal(thisWorks);
  });
  notWorks = {};
}

function printVal(val) {
  console.log(val);
}
why();