Inexplicable lack of articles: two examples

Question

I have stumbled upon two cases of article usage (better to say lack of it) I do not really understand. Both come from here

In one place the author writes:

This is not entirely practical, so I will at least break the code into logical sections that do fit on screen all at once.

Why not "on a screen", why word screen lacks here an article?

On another occasion he writes:

White space is free, use it to make your code look good.

Again, why not "a white space" (to refer to any white space) or "the white space" (to refer to all white spaces in the universe)?

Answer 1

These are both examples of computer programming lingo that someone living a few decades ago may have thought were strange but are common in modern English.

On screen

On screen is an idiomatic phrase that came about with the rise of computers. For clarity, we might even write it "on-screen." There isn't a general rule for why this came about that I know of. There are a number of such special phrases in English (where no article is used). You may just need to learn them.

White space

White-space is also idiomatic jargon, but it's a little easier to explain. "A white space" would mean one empty character. White space may or may not be countable (either a certain number of spaces and tabs or an amount of white space). When we say "white space" the word "space" does not refer to a single character, but a generic area of emptiness, which may be filled with either spaces, tabs, or something else.

To see it more clearly, remove the "white."

Space is free.

Makes perfect sense. It refers to an empty area of indeterminate size.

A space is free.

In computers this refers to a single space character.

The author you have referenced indicates that white space, whether made up of a bunch of spaces or tabs or one space, is always free.

Answer 2

You could in fact say on the screen and that would be perfectly fine. But you could also say on screen and that would be equally fine too. I can't explain why, but one thing I know for certain is that adverbial phrases in English tend not to have articles in them. For example:

Are these old methods still in use today?

Your comment that he looks stupid in this outfit is very much on point.

A white space and white space without an indefinite article in front of it actually mean two slightly different things. A white space would be a single white space character on your screen that you can literally type in into your computer with your fingers whereas white space without the article refers to the amount of blank or unfilled space on said screen or the printed page. The trick is to think of them as two separate words that mean different things.