<!-- CodeCopy Vanilla/UMD bundle -->
<link rel="stylesheet" src="//cdn.jsdelivr.net/npm/codecopy/umd/codecopy.min.css"></link>
<script src="//cdn.jsdelivr.net/npm/codecopy/umd/codecopy.min.js"></script>

<script>document.addEventListener('DOMContentLoaded', function (event) {
  codecopy('pre')
})
</script>

Hover the text to copy it. See on GitHub.

Also react version!