SyntaxError: let is a reserved identifier on firefox

Question

I am using those code below

\'use strict\';

jQuery(document).ready(function($) {
    function CMB2ConditionalsInit(context) {
        if(typeof context === \'un         


        

Answer 1

As you can see the let keyword isn't supported on FF yet: https://kangax.github.io/compat-table/es6/

You will need to change it to var, or transpile your code with babel