Hello. I'm new to XAMPP, I seem to have it mostly working. However, a number of my old programs are getting errors.
They seem to be coming from undefined variables, and variants of the theme, as best I can tell.
One of my first programs gets "Undefined index" errors, but otherwise seems to function, when using unfilled variables from a form. Other programs get undefined variable messages.
I saw that there is a setting to turn off these errors, which I'll do as long as it still shows other errors. But my real question is how important it is to define variables? Is it completely optional, optional but advised, or something that is important for some reason or another? In short, is it something I should start doing in my future programs, or something that can be left as is?
I haven't heard of any problems about this until now, but it seems pointless to have errors about something trivial.