You&#x27;ll get an errror :) (probably a syntax error)<p>You don&#x27;t need to hold off on using it but you should definitely use a compiler like Babel[1] to compile your ES6 code to ES3 for compatibility.<p>[1] <a href="https:&#x2F;&#x2F;babeljs.io&#x2F;" rel="nofollow">https:&#x2F;&#x2F;babeljs.io&#x2F;</a>