JSFiddle - React, Tailwind, and code Playground
HTML
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
<textarea id="test"></textarea>
<button id="button_test">Ok</button>
JavaScript
$(document).ready(function()
{
console.clear();
/* every 8 px */
$("#test").val("123e2oierhqwpoiefdhqwopidfhjcospid");
});
$("#button_test").on("click",function()
{
console.clear();
var length_area = $("#test").width();
var length_value = $("#test").val().length;
var index = Math.trunc(length_area/8);
var finalstr = $("#test").val().substring(0, index) + " " + $("#test").val().substring(index);
console.log(finalstr);
});