Think back to the last time you looked at an unfamiliar block of code. Did you immediately understand what it was doing? If not, you’re not alone – many software developers, including myself, find it challenging to grasp unfamiliar code quickly…
I once wrote a commit message the length of a full blog post comparing 10 different alternatives for micro optimization, with benchmarks and more. The diff itself was ten lines. Shaved around 4% off the hot path (based on a sampling profiler that ran over the weekend).
I can’t recall the exact change but a coworker did something five years very intentionally. The comments, the commit and everything described what they did but not why.
I think it was with side effects: true and I fixed a certain way we bundled things and I believe that could have solved the issue but I don’t know for sure :/
And sometimes code is not the right medium for communicating domain knowledge. For example, if you are writing code the does some geometric calculations, with lot of trigonometry, etc. Even with clear variable names, it can be hard to decipher without a generous comment or splitting it up into functions with verbose names. Sometimes you really just want a picture of what’s happening, in SVG format, embedded into the function documentation HTML.
Yeah. I advocate for self explanatory code, but I definitely don’t frown upon comments. Comments are super useful but soooo overused. I have coworkers that aren’t that great that would definitely comment on the most basic if statements. That’s why we have to push self explanatory code, because some beginners think they need to say:
//prints to the console
console.log("hello world");
I think by my logic, comments are kind of an advanced level concept, lol. Like you shouldn’t really start using comments often until you’re writing some pretty complex code, or using a giant codebase.
Sometimes when I don’t leave comments like that, I get review comments asking what the line does. Code like ThisMethodInitsTheService() with comments like “what does this do?” in the review.
So now I comment a lot. Apparently reading code is hard for some people, even code that tells you exactly what it does in very simple terms.
Fair. I guess in this case, it’s a manner of gauging who you’re working with. I’d much rather answer a question once in a while than over-comment (since refactors often make comments worthless and they’re so easy to miss…), but if it’s a regular occurrence, yeah it would get on my nerves. Read the fuckin name of the function! Or better yet go check out what the function does!
Worse, refactors make comments wrong. And there is nothing more annoying then having the comment conflict with the code. Which is right? Is it a bug or did someone just forget to update the comments… The latter is far more common.
Comments that just repeat the code mean you now have two places to update and keep in sync - a pointless waste of time and confusion.
Yes- exactly, they make comments wrong. But comments aren’t always a waste of time, like in legacy code, or just in general code that isn’t gonna change (mathematical equations too)
Comments are not always a waste of time, but comments that repeat or tell you what the code is doing (rather than why) are a waste. For legacy code you generally don’t have comments anyway and the code is hard to read/understand.
But if you can understand the code enough to write a comment you can likely refactor the code to just make it more readable to start with.
For code that does not change generally does not need to be read much so does not need comments to describe what it is doing. And again, if you understand it enough to write a comment to explain what it is doing you can refactor it to be readable to begin with. Even for mathematical equations I would either expect the reader to be able to read them or link to documentation that describes what it is in much more detail to name the function enough that the reader can look it up to understand the principals behind it.
You make some great points. Using smaller functions and breaking up your code in readable bits makes a huge difference and you will likely never need comments if you do it right 👍🏻
I think overusing comments is a non-issue. I’d rather have over-commented code that doesn’t need it, over undocumented code without comments that needs them. If this over-commenting causes some comments to be out of date, those instances should hopefully be obvious from the code itself or the other comments and easily fixed.
I understand what you’re saying and I mostly agree, but those few instances where a line of code is only slightly different and the comment is the same, can really be confusing.
Figuring out what the code is doing is not the hard part. Documenting the reason you want it to do that (domain knowledge) is the hard part.
One upvote is not enough.
I once wrote a commit message the length of a full blog post comparing 10 different alternatives for micro optimization, with benchmarks and more. The diff itself was ten lines. Shaved around 4% off the hot path (based on a sampling profiler that ran over the weekend).
I can’t recall the exact change but a coworker did something five years very intentionally. The comments, the commit and everything described what they did but not why.
I think it was with side effects: true and I fixed a certain way we bundled things and I believe that could have solved the issue but I don’t know for sure :/
Agreed.
And sometimes code is not the right medium for communicating domain knowledge. For example, if you are writing code the does some geometric calculations, with lot of trigonometry, etc. Even with clear variable names, it can be hard to decipher without a generous comment or splitting it up into functions with verbose names. Sometimes you really just want a picture of what’s happening, in SVG format, embedded into the function documentation HTML.
Yeah. I advocate for self explanatory code, but I definitely don’t frown upon comments. Comments are super useful but soooo overused. I have coworkers that aren’t that great that would definitely comment on the most basic if statements. That’s why we have to push self explanatory code, because some beginners think they need to say:
//prints to the console console.log("hello world");I think by my logic, comments are kind of an advanced level concept, lol. Like you shouldn’t really start using comments often until you’re writing some pretty complex code, or using a giant codebase.
Sometimes when I don’t leave comments like that, I get review comments asking what the line does. Code like
ThisMethodInitsTheService()with comments like “what does this do?” in the review.So now I comment a lot. Apparently reading code is hard for some people, even code that tells you exactly what it does in very simple terms.
Fair. I guess in this case, it’s a manner of gauging who you’re working with. I’d much rather answer a question once in a while than over-comment (since refactors often make comments worthless and they’re so easy to miss…), but if it’s a regular occurrence, yeah it would get on my nerves. Read the fuckin name of the function! Or better yet go check out what the function does!
Worse, refactors make comments wrong. And there is nothing more annoying then having the comment conflict with the code. Which is right? Is it a bug or did someone just forget to update the comments… The latter is far more common.
Comments that just repeat the code mean you now have two places to update and keep in sync - a pointless waste of time and confusion.
Yes- exactly, they make comments wrong. But comments aren’t always a waste of time, like in legacy code, or just in general code that isn’t gonna change (mathematical equations too)
Comments are not always a waste of time, but comments that repeat or tell you what the code is doing (rather than why) are a waste. For legacy code you generally don’t have comments anyway and the code is hard to read/understand.
But if you can understand the code enough to write a comment you can likely refactor the code to just make it more readable to start with.
For code that does not change generally does not need to be read much so does not need comments to describe what it is doing. And again, if you understand it enough to write a comment to explain what it is doing you can refactor it to be readable to begin with. Even for mathematical equations I would either expect the reader to be able to read them or link to documentation that describes what it is in much more detail to name the function enough that the reader can look it up to understand the principals behind it.
You make some great points. Using smaller functions and breaking up your code in readable bits makes a huge difference and you will likely never need comments if you do it right 👍🏻
I think overusing comments is a non-issue. I’d rather have over-commented code that doesn’t need it, over undocumented code without comments that needs them. If this over-commenting causes some comments to be out of date, those instances should hopefully be obvious from the code itself or the other comments and easily fixed.
I understand what you’re saying and I mostly agree, but those few instances where a line of code is only slightly different and the comment is the same, can really be confusing.
TempleOS: Hold my communion wine