Does anyone have a preference about line length in computer code?
It looks like the typical 80-column recommendation goes back to 1928. Linus Torvalds suggested extending it to 132. (More details here.)
I’m thinking about switching my editor’s guideline from 80 to 100, because it’s a little annoying when my text goes over the line in my editor. It’s usually only happens when my comments have a long URL in them or when I’m building long, single-line strings.
For now, I put this in my .vimrc to highlight both the 80th and 100th column:
set colorcolumn=80,100
and a tox.ini in my projects to stop the Python linter from complaining:
I’ve toyed around with this too and eventually landed on using two guidelines: one at 80 and another at 120. I treat the 80 as a friendly suggestion and the 120 as a wrap. This works pretty well because it’s a reasonable length for the screens I use, and when I revisit code in Gitlab, keeping it under 120 makes it easy to read in the browser.
An 80 character limit doesn’t make a lot of sense anymore, imo. I feel like it discourages some really useful practices like clear and descriptive variable names. If I’m trying to stay under 80 characters, I find myself using more generic variables, and I pay the price a few months later when I’m ready to extend that older code.
This is a big question, especially when you’re coding in groups or at a big company somewhere. Personally, it feels like it’s language-dependent. Python’s a bit fussy with formatting so it wants what it wants.
Most other languages these days don’t mind so much.
I wrote an article which to me applies to the topic. I prefer creating two big columns within most languages I do. My preferred 2nd-column setting is 45 characters over. See Figure 2 of that article to see what I’m talking about. In short, assignments force the use of that second column; all assignments may be quickly identified.
Obviously, this can create longer lines in many cases. I tend to promote adding a third column over around 70 perhaps for the beginning of line-specific comments.
Because of the squash-for-readability rule, this then makes some lines longer than you’d otherwise have. The upside is that you usually then get to read an entire function within one screenful (vertically).
Prettier isn’t perfect, but it’s good enough, and I can press a key to reformat the file. My main goal is having it be skimmable and avoiding too much thinking about it.
Here’s what their sample code looks like with those settings:
function HelloWorld({
greeting = "hello",
greeted = '"World"',
silent = false,
onMouseOver,
}) {
if (!greeting) {
return null;
}
// TODO: Don't use random in render
let num = Math.floor(Math.random() * 1e7)
.toString()
.replace(/\.\d+/gi, "");
return (
<div
className="HelloWorld"
title={`You are visitor number ${num}`}
onMouseOver={onMouseOver}
>
<strong>
{greeting.slice(0, 1).toUpperCase() +
greeting.slice(1).toLowerCase()}
</strong>
{greeting.endsWith(",") ? (
" "
) : (
<span style={{ color: "grey" }}>", "</span>
)}
<em>{greeted}</em>
{silent ? "." : "!"}
</div>
);
}
