JSFiddle - React, Tailwind, and code Playground

HTML

<input id="user" />
<input id="age" />

<button id="load">
  Load Cookies
</button>

<button id="save">
  Save Cookies
</button>

<div id="out">
  Output
</div>

JavaScript

var myCookies = {};

document.getElementById("load").addEventListener("click", loadCookies);
document.getElementById("save").addEventListener("click", saveCookies);

function saveCookies() {
  myCookies["_uuser"] = document.getElementById("user").value;
  myCookies["_uuage"] = document.getElementById("age").value;
  //Start Reuseable Section
  document.cookie = "";
  var expiresAttrib = new Date(Date.now() + 60 * 1000).toString();
  var cookieString = "";
  for (var key in myCookies) {
    cookieString = key + "=" + myCookies[key] + ";" + expiresAttrib + ";";
    document.cookie = cookieString;
  }
  //End Reuseable Section
  document.getElementById("out").innerHTML = document.cookie;
}

function loadCookies() {
  //Start Reuseable Section
  myCookies = {};
  var kv = document.cookie.split(";");
  for (var id in kv) {
    var cookie = kv[id].split("=");
    myCookies[cookie[0].trim()] = cookie[1];
  }
  //End Reuseable Section
  document.getElementById("user").value = myCookies["_uuser"];
  document.getElementById("age").value = myCookies["_uuage"];
}