It’s tricky to find an objective optimum. Personally I’ve been happy with up to 100 chars per line (aim for 80 but some lines are just more readable without wrapping).

But someone will always have to either scroll horizontally or wrap the text. I’m speaking as someone who often views code on my phone, with a ~40 characters wide screen.

In typography, it’s well accepted that an average of ~66 chars per line increases readability of bulk text, with the theory being that short lines require you to mentally «jump» to the beginning of the next line frequently which interrupts flow, but long lines make it harder to mentally keep track of where you are in each line. There is however a difference between newspapers and books, since shorter ~40-char columns allows rapid skimming by moving your eyes down a column instead of zigzagging through the text.

But I don’t think these numbers translate directly to code, which is usually written with most lines indented (on the left) and most lines shorter than the maximum (few statements are so long). Depending on language, I could easily imagine a line length of 100 leading to an average of ~66 chars per line.

> the theory being that short lines require you to mentally «jump» to the beginning of the next line frequently which interrupts flow, but long lines make it harder to mentally keep track of where you are in each line.

In my experience, with programming you rarely have lines of 140 printable characters. A lot of it is indentation. So it’s probably rarely a problem to find your way back on the next line.

I don’t think code is comparable. Reading code is far more stochastic than reading a novel.

For C/C++ headers I absolutely despise verbose doxygen bullshit commented a spreading relatively straightforward functions across 10 lines of comments and args.

I want to be able to quickly skim function names and then read arguments only if deemed relevant. I don’t want to read every single word.