JSFiddle - React, Tailwind, and code Playground
JavaScript
var str = "Thisasdfasdfasdfasdfasdf is a sample string";
var len = str.length;
var ind = str.indexOf(' ', Math.floor(str.length / 2) - 1);
var str1 = str.substr(0, ind);
var str2 = str.substr(ind);
alert(str1 + ' ===> ' + str2);