Now that you know about the object-oriented features of JavaScript, such as prototypes and inheritance, and you have seen some practical examples of using the browser objects, let's move forward, or rather, move a level up. Let us have a look at some common patterns of JavaScript utilization. First, let's define what a pattern is. In short, a pattern is a good solution to a common problem.

Sometimes when you are facing a new programming problem, you might recognize right away that you've previously solved another, suspiciously similar problem. In such cases, it is worth isolating this class of problems and searching for a common solution. A pattern is a proven and reusable solution (or an approach to a solution) to a class of problems. Sometimes a pattern is nothing more than an idea or a name, but sometimes just using a name helps you think more clearly about a problem. Also, when working with other developers in a team, it's much easier to communicate...