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Comment by pjmlp | Hacker News Reader

I cringe every single time I see a for loop for what System.arraycopy () has been providing since early days.

For better or worse, it shows me that the author isn't that into Java.

I cannot for my life remember the argument order, so I write the manual code and let IntelliJ convert it.

Doesn't autocomplete show the arguments? I usually use Netbeans when I write Java, so no idea if InelliJ is just that bad.

IntelliJ definitely shows the arguments lol

It shows the argument names and even highlights the current one where the cursor is. But sometimes my thought process is just different.

In Java, it's src array, src offset, dest array, dest offset, length. It's a natural order of from, to.

It's C memcpy() that's the odd one out by putting the destination before the source.

memcpy argument order matches the left-to-right arrangement of assignment. lhs=rhs is rhs is copied to lhs. memcpy(lhs,rhs) is the contents at rhs is copied to lhs.

British people generally don't, but Americans very often use "to...from".

They do, and it's jarring!

Even though I find memcpy and friends to be perfectly logical using the assignment analogy suggested by thwarted, I often need to re-read english sentences written that way.

> I cringe every single time I see a for loop for what System.arraycopy () has been providing since early days.

The worst thing is, that System.arraycopy() is an optimized JNI call which is much faster than copying it by hand [1].

> For better or worse, it shows me that the author isn't that into Java.

The thing is though, most of the time arrays in Java are used because of performance. Or maybe ignorance. Because why would anyone voluntarily give up all the comforts of a List<T>? It's not that Collections are very hard to find in the documentation. And most of the IntelliJ suggest switching to a Collection anyway.

1. https://www.javaspecialists.eu/archive/Issue124-Copying-Arra...

Or it might be that the person has used multiple programming languages, across which the order/meaning of copy arguments varies a lot, and thus prefer to not remember the decision of each language (if not for writing (at which point the IDE could help), then for reading). Whereas a loop is always easy to read and write equally in all languages, and it's really not unreasonable to expect it to perform well enough (if not as good as System.arraycopy, then at least good enough to be insignificant compared to the actual important logic in the code).

Given that I have programed dozen of languages since 1986, and have to jump between C#, Java, C++, Typescript, Transact SQL and PL/SQL for work, plus whatever is needed to keep the customer happy, isn't an argument I would sympathise with in code reviews.

Yet, somehow I doubt you write perfect code in all those languages. Do you cringe at yourself and conclude you just don’t care also?

There are more options than "write perfect code" and "not even attempt to learn how to write idiomatic code".

Yeah, of course. But maybe you should just be happy to share knowledge with those lacking it, rather than cringing and making some kind of personal judgement of them.

No I don't, and when someone cringes looking at my code, I shut up, apply the fix and get to improve my skills on the language, instead of excusing myself.

So you agree you should be judged as someone who doesn’t care in those cases also, right? You didn’t mention anything about people excusing themselves initially, just that you judged them. I just hope you hold yourself to the same standard.

So is life, made up of judgments, not always fair.

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