JSFiddle - React, Tailwind, and code Playground
by AdamDrummond
JavaScript
var str = "<html><body></body><div></div><body>Junk</body></html>";
var match = str.match(/(<\/body>)/i);
var lastIndex = str.lastIndexOf(match[match.length - 1]);
var newContent = str.slice(0, lastIndex) + "bar" + str.slice(lastIndex);
alert(newContent);