As you learned in Scope, Namespaces, ‘use strict’, it’s considered good practice to use a self-invoking function to wrap strict mode compliant code, often called the strict mode pragma.
(function(){ "use strict"; // Strict code here }());
But how do you declare a global?
If you do the following, it will assume the window object in the browser and also create a global in Node.js and where you may not have a window object.
If you know you will be in a browser, you can assume the window object, or pass in the global:
References
How to declare global variables when using the strict mode pragma
