>>For instance, it can be a problem to have many global variables. (The application object is a single global variable, which stores, in its properties, many different things.)
>
>PMFJI,
>
>What type of kind of a problem you can have with many global/public variables? I do use public variables in my application and would like to know when (at how many of those) I should start changing from public variables to one object.

The problem with global variables lies in any piece of code being able to change the content at any time, especially unexpectedly.

An object can control the circumstances of property changes. Further, a class has property descriptions as well as the property name and value. This makes for self-documenting code. Safer than public variables and more descriptive means better in my opinion.