JSFiddle - React, Tailwind, and code Playground
JavaScript
var url = "http://wwww.example.com";
//var url = "http://wwww.example.com/fr/about/what";
var arr = url.split("/");
var lang = (arr[3] != undefined && (arr[3].length == 2 || arr[3] == "eng") ) ? arr[3]: "eng";
alert(lang);