JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
<div id="loggedinstore">
  <span>DSNBG</span>
</div>

JavaScript

// fill it 
var storefullnames = {};
storefullnames["dsffm"] = "Designstore Frankfurt"; 
storefullnames["dsmch"] = "Designstore München"; 
storefullnames["dsnbg"] = "Designstore Nürnberg";

// get value from markup 
console.log($('#loggedinstore > span').html()); // DSFFM
var storekey = String($('#loggedinstore > span').html().toLowerCase());
//console.log(storekey); // dsffm 
//console.log(storefullnames["dsffm"]); // Designstore Frankfurt
//console.log(storefullnames); // Object { dsffm="Designstore Frankfurt",  dsmch="Designstore München",  dsnbg="Designstore Nürnberg"}

// should print Designstore Frankfurt
alert(storefullnames[storekey]); // undefined 
//console.log(storefullnames.storekey);  // undefined