JSFiddle - React, Tailwind, and code Playground

HTML

<h2 id="hello"></h2>
<p id="text"></p>
<button onclick="setLang('en')">English</button>
<button onclick="setLang('ar')">عربي</button>

JavaScript

var ar = { hello: "مرحباً!!", text: 'تغيير اللغة' };
var en = { hello: 'Hello!!', text: 'Change language' };
var language = ar;

function changeText(){
 for (const key in language) {

     document.getElementById(key).innerText = language[key];
  }
}
changeText(); 

var setLang = function (lang){
  lang === 'ar' ? language = ar : language = en;
	 changeText(); 
}