Modernizr load CDN script with local fallback

modernizr-cdn-fallback.js

Modernizr.load([{
    load: [
        '//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js'
    ],
    complete: function() {
        if (!window.jQuery) {
            console.log('## CDN Failed - Loading local version of jQuery.');
            Modernizr.load('/js/jquery.min.js');
        };
    }
}]);

The trick is (for other scripts), on the if statement, you have to check for something it loads in.
If it is coded correctly, you can do a similar window.xxxxx check

Example

if (typeof($.fn.owlCarousel) === 'undefined')

This checks to see if it created its global function.