JSFiddle - React, Tailwind, and code Playground

HTML

<span></span>
<button>click me to show new varibale change</button>
<input type="text" id="inputTxt" />

<div style="display:none">new variable</div>

JavaScript

$(document).ready(function(){
    
     $('button').click(function(){
        var text = $('div').text() ;
        $("input[type=text]").val(text)
    });
    
    $("input[type=text]").change(function(){
        $('span').text($(this).val());
    });
  
});