In my freshman year in college, I started work on my first intranet application. The files in the main directory of the partially functioning application looked something like Figure 1.1:
Figure 1.1. The directory structure of my first web application titled “Online Exams”
Looking at the file names in this directory, you can see that I used some very similar names, such as exam.php, exam1.php and examfile.php. The purpose of that naming convention was to create new versions of my application without losing the old, working logic—in case the new ideas failed! I assumed that, because I understood what each of those files did, ...