The samples we have just seen are an example of tight coupling between the generated HTML content (that contains JavaScript code in script blocks) on your web page, and the actual running JavaScript. You may argue, however, that this is a design flaw. If the web page needed an array of contact emails, then the JavaScript application should simply send an AJAX request to the server for the same information in JSON format. While this is a very valid argument, there are cases where including content in the rendered HTML is actually faster.

There used to be a time where the internet seemed to be capable of sending and receiving vast amounts of information in the blink of an eye. Bandwidth and speed on the internet were growing exponentially, and desktops were getting larger amounts of RAM and faster processors. As developers during this stage of...