A robust & optimized ES3-compatible polyfill for the String.prototype.codePointAt method in ECMAScript 6.

Other polyfills for String.prototype.codePointAt are available:

• http://norbertlindenberg.com/2012/05/ecmascript-supplementary-characters/#String by Norbert Lindenberg (fails 2 tests)
• https://gist.github.com/slevithan/2290602 by Steven Levithan (fails 8 tests)
• https://github.com/paulmillr/es6-shim/blob/771e98e789292706d2435e4e10ffbe45edf40da6/es6-shim.js#L166-L177 by Paul Miller (passes all tests)

In a browser:

<script src="codepointat.js"></script>

Via npm:

npm install string.prototype.codepointat

Then, in Node.js:

require('string.prototype.codepointat');

// On Windows and on Mac systems with default settings, case doesn’t matter,
// which allows you to do this instead:
require('String.prototype.codePointAt');

A polyfill + test suite for String.fromCodePoint is available, too.

Mathias Bynens

This polyfill is available under the MIT license.