You must log in or register to comment.
As a software engineer: actually there is no need for a number of people as a power of 2 unless you need exactly 1 byte to store such information which sounds ridiculous for the size of Whatsapp
It’d make sense at protocol level. Otherwise, yeah, even bit-size database columns end up being stored as a word unless the engine compacts it.
evenly specific
A previous version of this article said it was “not clear why WhatsApp settled on the oddly specific number.” A number of readers have since noted that 256 is one of the most important numbers in computing, since it refers to the number of variations that can be represented by eight switches that have two positions - eight bits, or a byte.
Lol, weird way to say that 256 is a power of two, and computers operate in base two.
Their definition is a lot better.
It’s a pretty succinct explanation that links what it is to something most people have heard of (a byte).
It used to be a way bigger deal when computers were very memory scarce, if you needed to say, represent 1024 values, that means you’d use 10 bits or 2 bytes, the remaining 6 bits could be used to store other related information like flags but more often than not it would be waste (unused values that still have to be represented as 0s)
These numbers are pretty arbitrary nowadays but they still show up a lot in computing. They didn’t choose 256 so they could represent it in a byte, the real reason is probably that groups larger than 256 can’t realistically be managed by users.
That’s my 2¢ anyways.
Tbf saying it that way brings a visual metaphor. Simply giving it as a mathematical definition would leave it feeling just as arbitrary.
Shout out to Castlevania II, where you can hold anywhere from 0 to 256 laurels. Yes, you read that right – 256, not 255. I inspected RAM to double check. It’s a 16-bit word on an 8-bit system with a maximum value of
0x100. They could have used 8 bits instead of 16. But no, they really did choose this arbitrary number.how can you hold 0 laurels? that’s different from not having laurels?
the number of laurels in your inventory is stored as an integer from 0 to 256.
I hate this. I love this.
If I ever make a game I might put stuff like this in it.
Having made a few games back in the day, this isn’t something you add on purpose, this is something that you screwed up, are going to “fix later”, then realize it’s too much hassle to rewrite 45% of your code and you just raise the minimum spec requirements a bit to compensate.
“I inspected RAM to double check.”
That’s an unhinged level of commitment. Respect — I dig it
Maybe they keep some other data in the same space using bitmask?
Even if true, 256 would be a waste of the range. 255 would make sense if trying to stay in one byte, using a whole different data type to get one extra bit just to hold 256 instead of saying “screw it, let’s go to 511” even while using other bits.
It’s just a very weird thing to do to pick 256 as a value limit back in those days (also oddly specific now, but for different reasons)
plausible, but my experience from dissecting these kinds of games is that they tend not to be as space efficient as you’d think they could be if they were the kaze emanuar type. The fact that they opted to have 257 distinct values for the laurels suggests to me that they weren’t prioritizing space efficiency.
My best (wildly speculative) guess is that a designer, knowing 256 is a common limit, wasn’t thinking carefully and said the maximum value should be 256 (instead of 255), and then an overly pedantic coder implemented this to the letter while rolling their eyes.
Currently in the industry - it’s exactly this. It’s a communication issue between the programming team and other teams, where designers freely speak for design, artists freely speak for art, etc. but it’s much harder for programmers to speak for implementation since it’s usually in reference to somebody else’s work, and when designers get offended or defensive or dismissive of the non-designer requesting 256 be changed to 255, then it stops being worth it.
For example, we made an absolutely mint UI backend, it was data driven with editors so anyone could whip up a new UI for the next feature without needing programmers. The design team were like “damn, I hear how complicated this thing was to build, so let’s make the programmers lives easier by not using it and only asking for simple bespoke stuff”. Telling them “the investment has already been paid for so please use it” was tantamount to telling them how to do their job while being ungrateful they had considered us, furthering the communication breakdown.
Yes I’m bitter and tired. It’s easier to use a short for 256 instead of arguing to have my opinion considered
Sounds like such a flex move
It also has the second best NES soundtrack, after The Guardian Legend.
In the top ten, with Blaster Master, and Batman.
I’ve never given TGL a proper listen, though I have the game for NES. Thanks for the recommendation!
Read it in the (old) avgn voice…
Numbers guy here, I can confirm 256 is an evenly specific number, and not an oddly specific number.
But is it Numberwang, Mr. Numbers Guy?
User name checks out
Oh you are the numbers guy ? Name every number
0, 1, 2, 3, 4, 5, 6, 7, 8, 9
So simple yet so effective as an answer
I’m going for the boring but practical answer: x and x . Obviously the second set is doing the heavy lifting.
You should know your limits
nerd
Ha, got eem
As the numbers guy. Do you remember the name of the site that can tell you the what a given number is often associated with?
Wikipedia often has disambiguation pages for numbers that may be helpful in a search like this (https://en.m.wikipedia.org/wiki/71).
WolframAlpha is good for identifying numerical properties of numbers (https://www.wolframalpha.com/input?i=71).
OEIS has a searchable set of sequences (https://oeis.org/search?q=71&language=english&go=Search)
I fear that none of these is what you’re looking for, though. My attempts to find something that sounds like what you want mostly turned up resources on numerology, and at least one article apparently about how the meaning of numbers is radically different between cultures.
No that doesn’t seem to be it. Thanks for trying anyway.
My brain is going to OEIS or angel numbers which are both like total opposites. Number theory or numerology, take your pick.
Oh yeah well if you’re some sort of numbers guy, answer me this: I think you’re name is super cool, and makes me wonder, is there a largest prime you can make listing digits of pi starting from the beginning. There’s gotta be infinite right?
Well, three is prime and pi starts with a three, therefore, even if there’s larger primes, there is one which is the largest. QED.
deleted by creator
Unless there isn’t one that’s the largest because there are infinite primes.
You started at zero and went to infinity. If you start at infinity and go to zero then the first prime you got is the largest. QED.
I can no longer tell if these are bits. 🫠
(Yes, this is a bit. 💜)
(Thank you for the kindness of clarity ❤️ I may now be at peace.)
That’s what she said…
deleted by creator
Pi is suspected to be a normal number (though this has not been proven). If it is normal, it’s likely that integers comprised of the first N digits of pi will be just as likely to be prime as comparable large integers. I suspect but cannot prove that there are infinitely many prime numbers whose digits are the first N digits of pi (with or without the leading 3).
I remember being puzzled by this and many other numbers that kept cropping up. 32, 64, 128, 256, 1024, 2048… Why do programmers and electronic engineers hate round numbers? The other set of numbers that was mysterious was timber and sheet materials. They cut them to 1220 x 2440mm and thicknesses of 18 and 25mm. Are programmers and the timber merchants part of some diabolical conspiracy?
Powers of two are the roundest of numbers.
They’re not round, they’re square!
Slow Clap Well done!
Only every other one…
Much later in my career I came to appreciate the beauty of this system and the link with hexadecimal. I had to debug a network transmitted CRC that was endian flipped and in that process learned that in the Galois Field of two, 1+1=0 which feels delightfully nonsensical to a luddite.
32, 64, 128 etc. are all round numbers, counting in binary. They are powers of two. Since computers work in binary, they make logical sense.
1220mm is 4ft, and 18 and 25mm are three-quarters of an inch, and an inch respectively.
They were making a joke. That being said, im not familiar with lumber or imperial<->metric conversions so their second point was lost on me, so thanks.
They just do it to look cool in front of their developer friends.
Pretty much this…
Once upon a time, sure, you might have used an 8 bit char to store an array index and incur a 256 limit for actual reasons…
But nowadays, you do it because 256 is a “cool techy limit”. Developers are almost all dealing with at least 32 bit values, and the actual constraints driving smaller values generally have nothing to do with some power of two limitation.
Timber is actually cut in inches. That’s why the odd numbers.
This isn’t a “tech article”, it’s an article about tech. This is a normie article from a normie news outlet for normie readers.
Also from the article:
A previous version of this article said it was “not clear why WhatsApp settled on the oddly specific number.” A number of readers have since noted that 256 is one of the most important numbers in computing, since it refers to the number of variations that can be represented by eight switches that have two positions - eight bits, or a byte. This has now been changed. Thanks for the tweets. DB
That weird ass explanation with switches and “one of the most important numbers” still sounds absolutely clueless.
Still, it works well for “normies”…
I liked the switches analogy! Generally about binary though; I agree it doesn’t connect back to the number of users application.
And yeah most important number…sounds like they were quoting an LLM.
“Quoting” is generous.
One of the most important numbers? I’d argue the most important number in computing is either 1 or 0…
What the fuck is a power of 2??? I’m vibe coding python AI.
Isn’t python a snake? /s vibecoders wouldn’t know
What do you bet that if you were Vibe coating in python it would import a library so it could do zero indexing again?
Vibe coating in python
I coat my python every day winknwink
God that sounds like some shit you’d read in a gibson novel from the 90s.
There are only 10 kinds of people in this world…
One is one of them
That quote really is the problematic part. The part about switches is fine - it’s an attempt to explain tech to a “normie.” But for a tech writer to ever say it’s not clear why they settled on 256 is worse than embarrassing. They had to be corrected by tweets.
Anyone whose ever had an intro to computers class has had a computing professional explain computers using simple language and analogies. That’s the way this kind of thing should work. It sounds like this author has no more clue about computing than the target audience, which isn’t going to work out well for the reader.
If you look what the last articles for the independent Doug Bolton (the guy who wrote the stuff in question) wrote, it was Condom discovered inside woman’s appendix, and afterwards he only wrote for “Movers & Makers Cincinatti” and some stuff looking like crawler bait for “Old Times Music” so i’m pretty sure the Independent didn’t want him anymore
Maybe he’s a vibe journalist.
Honestly chat gpt would probably be better at this.
That is both sad and likely accurate.
It doesn’t really matter that it’s a “normie article for normie readers”. Writing articles is journalism. Not knowing 256 offhand? Permissible. Being a journalist who wrote an article and didn’t even do the bare bones of research? You’re still a bad journalist, and as callous as it is, you should lose your job and livelihood. Bad journalism is too dangerous to just let it fester like this.
The newspaper he was writing for is a major publication he absolutely could have asked someone.
The problem here is the newspaper didn’t care enough about the article to put anyone on it who is even remotely familiar with technology. They probably thought of it as just some throwaway piece to fill out a bit of space. Which to be fair it would have been had it not been for that comment.
It used to be common for uh, writers, journalists, to have at least basic familiarity with what they’re writing or reporting on.
Its not like this is journalistic malpractice, spreading lies, fabricating a quote, supporting a bs narrative by being very selective with context and such…
… but it is pretty embarrassing.
People seem to constantly confuse ‘i use computer technology’ with ‘i understand how computer technology works’.
Like uh, Gen Z and A are the most digital, online generations yet… but many of them can’t type on a keyboard, have no idea what a file/folder structure is.
I think you’re highlighting two different problems here.
I agree that Gen Z and younger are, on average, far worse at basic computer skills than many seem to assume. It makes me reflect on my tech-learning throughout my childhood, as a Millennial. I think that part of it is that many erroneously assume that because Gen Z has grown up online, that this will lead to proficiency, but the kind of tech they’ve been exposed to is largely walled gardens and oversimplified UIs. That assumption of proficiency leads to scenarios where their lack of skill is only discovered when they enter college, or the workplace. I am astounded at the prospect of people not even knowing the difference between “Cut and Paste” and “Copy and Paste”. It’s grim.
The poor quality of journalism may be linked to this, but I think it’s larger than that. It seems like it’s not a great time to be a journalist at the moment (my writer friends tell me that increasingly, the only work they’re able to find is copy-editing AI shit). Private equity is fucking up so much of the world — journalism included. Polygon is an example of an outlet that was apparently sustainably profitable, before it was sold and experienced mass lay-offs; an individual company’s success doesn’t matter to the big conglomerate that owns it. I know that other journalistic companies have fallen to the same fate too.
It also seems that tech journalism ends up being especially shit. I didn’t start noticing it properly until I watched this podcast episode from “Tech Won’t Save Us”. The TL;DW of it is that tech journalists like Kara Swisher like to pretend that they speak truth to power, and fire hard-hitting questions at big tech people, when that’s patently bullshit and it’s clear that they only get the access that they do by playing softball with the powerful. We can’t blame a few individuals for the entirety of the tech journalism problem, but I reckon it’s a big part of it when so many of the established, big names in this space don’t seem interested in actually doing tech journalism (and smaller names who want to ask journalistically interesting questions don’t get platforms or access to ask those questions).
Our information ecosystem is not in a great place. I’ve found it tremendously beneficial to curate the news and information I’m exposed to (praise be RSS), but that has been a gradual process of actively working to notice good journalism in the world and build up my mental “rolodex” of people whose perspectives I trust to be worthwhile (even if I don’t necessarily agree with said perspectives). However, this is an area that I care deeply about, and thus it feels worthwhile to spend that energy to curate my infosphere. Most people won’t have the inclination or energy to do this work, which is unfortunate.
I almost entirely agree with what you’ve said here, I just didn’t feel like writing out all the nuances, and was trying to just do a surface level analogy.
The only part where I even sort of maybe disagree is… there are actually good tech news sources, they just tend to be either fairly or highly specialized, and/or pretty niche, literally just a guy, or a couple people, running a website basically like its still Web 1.0 days.
But absolutely yes, the broader audience that an outfit appeals to, the broader scope of things they try to cover… its a joke, doing comprehensive reviews of everything would take a whole bunch if teams of specialists, so… most don’t even bother, and just link to somebody else who did that, and try to summarize it … and thats a best case scenario.
It is truly horrendous with video game journalism.
Beyond the surface level stuff of seemingly arbitrary and nonsensical review scores, the incestuous access journalism aspect of it that turns most of them into just advertising…
Almost none of these people offer a meaningful critique of like, the business strategy, the corporate culture, the deals between companies, the astoundingly high usage of contractors and just endemic, obvious galactic levels of incompetence management shows all the time.
Again, there are a few exceptions to this, they’ll cover some obviously heinous shit like sexual harassment and absurd crunch seasons, they’ll report on unions trying to form, and there are a few actually decent investigators…
… but by and large, there is basically no investigative journalism into say, an utterly collapsed, decade spanning, $400 million dollar game that just flops in a month… not on the level that I feel is journalistically called for there, which would be roughly ‘this is Enron’, ‘this is Lehman Brothers’.
They live in this silly nonsense world where the gaming industry is fucking huge and important, but they still mostly cover it like disaffected former fanboys/girls, rather than taking it as seriously as it should be taken.
Because there is no meaningful dissection of how truly idiotic and evil just now routine AAA corpo game publisher logic works, at like a macro to microeconomic comprehensive analysis level… we instead get the masses dramatically oversimplifying things on that front, and then focusing waaaaay too much on whether or not its ok for characters to have pronouns.
Like, me, I am the only person I am aware of who has been saying:
Kernel level anti cheat is not actually necessary, it doesn’t even achieve what it purports to, thus, it just serves as a way to to maintain a corporate grip over the platform (Windows) of the PC gaming market.
Similarly, the entire real time ray tracing paradigm of Nvidia/Unreal Engine is also a fucking scam, though I am at least seeing more people do comprehensive breakdowns on why that is the case, of course the PC hardware reviewers are very fed up with this by now… but still only a few go into the massive economic impacts of that and thus broad societal implications.
…
There, your essay provoked my own rant-essay, lol.
I could write on this for days if my wrist was so fucked, bleck.
Yep very weird, should have been 255.
No, you can’t have a group of zero, so the counter doesn’t need to waste a position counting zero.
0 is reserved for the FBI agent listening in.
It’s an ICE agent now
Nah, ICE agents don’t care about evidence.
Also they can’t use computers anyway. They just publicly post on social media. It’s considered secure because no one likes them enough to follow them.
Tell that to the Castlevania 2 devs. https://lemmy.ml/comment/19720906
If you ever create a system where the number of users is “group.members - 1” everywhere in the code, I’d be very disappointed in you and deny that PR.
On another note; I doubt WhatsApp are so concerned with performance they are actually limiting the number of group members by the data type.
But it wouldn’t be like that though would it. It would be public group.members() and the u8 would be private.
If all the millions of groups are saved on a central database then making the size a u8 isn’t really that weird
I hadn’t thought about it on their server side tbf. But the more i think about it maybe there are other compounding reasons to keep group sizes small, such as the exponential number of links in a growing network and such. But, that is all beyond my knowledge area.
Sure you can. It’s a group that exists, but it has 0 participants.
You probably could, if everyone got banned or something
You cannot also have a group of 1, therefore either is 255 or 257. 256 is oddly specific (or the code was made by an intern)
Sure you can.
Oh. At this point I’m not sure what is worse :/
I mean, should the group and all the messages get deleted when the second to last person leaves? it only makes sense to let it stay as a 1 member group
In this case the limit was entirely arbitrary.
The programmers were told to pick a limit and they liked 256. There are issues with having a large number of people in a group, but it wasn’t a hardware limit for this particular case.
But it’s still not oddly specific, they picked a nice round number
If it’s engagement bait, it’s working.
Engagement byte
So far at least, I’ve found this much more charming than culture war bait.
Enragement bait.
They’re the same picture.
I wish we could see what outlet it was for context
The independent
Thanks :)
pregagenant
Still odd, I very much doubt they use a 8bit variable to set this limit. What would this bring ?
Still odd
Actually, it’s even.
When the program is running it’s probably stored with 32 or 64 bits, but that probably isn’t the case for the network packet layout. I can imagine them wanting to optimize network traffic with over 3 billion users even if it’s just a small improvement.
Also TIL that Erlang’s VM apparently stores strings as linked lists of chars. Very strange.
You know you’re a tech nerd when 256 sounds more even than 250 or 300. 😅
It kind of is “more even”.
256 is just 2⁸
250 is 2x5³
300 is 2²x3¹x5²Any division of 256 with an integer and integer result will be even. Most divisions of 250 and 300 with an integer and integer result will be odd.
Even that is odd.
256/256 is not even
Disregarding the trivial exceptions… waves hands
Or a maths nerd!
Or when it’s bothering you that it’s 256 and not 255… aren’t we counting 0 anymore? :/
Or when it’s bothering you that people forget the difference between counting and indexing.
You can index to 255 in an 8 bit number, but your count is still 256 when you get there.
Fair point 😄
If there are two things I hate in this world, it’s off by one errors.
https://en.wikipedia.org/wiki/Zero:_The_Biography_of_a_Dangerous_Idea
One of the most annoying books I ever read. Every page made me feel stupider and more uneducated.
Superficially, this book looks like one that I would enjoy (if not for your anti-recommendation causing me to steer clear). Because of this, I would wager that you would have an interesting answer to “if someone was considering the above book, what’s a book you would recommend they read instead?”.
In the spirit of “take a book, leave a book”, one of my favourite non-fiction books for a general audience is “Power, Sex, Suicide: Mitochondria and the Meaning of Life”. This recommendation is beyond the topic of the current thread, but in terms of enjoyable books that made me feel smarter, I love this one; I read it as a biochemistry undergraduate, and I was surprised at how much I learned from it.
Thanks for the suggestion.
That’s a super old article as well.
They got rightfully roasted in the comments for not knowing even the most basic things about computing.
I remember thinking something similar when I was a kid modding Starcraft. Max levels/ranks in researching was 256 and I always wondered why such a weirdly specific number.
So, I get that 256 is a base 2 number. But we’re not running 8-bit servers or whatever here (and yes, I understand that’s not what 8-bit generally refers to). Is there some kind of technical limitation I’m not thinking of where 257 would be any more difficult to implement, or really is it just that 256 has a special place in someone’s heart because it’s a base 2 number?
Because 256 is exactly one byte. If you want to add a 257th member, you need a whole second byte just for that one person. That’s a waste of memory, unless you want to go to the 64k barrier of users per chat.
Except that they’re almost certainly just using
int, which is almost certainly at least 32 bits.256 is chosen because the people writing the code are programmers. And just like regular people like multiples of 10, programmers like powers of 2. They feel like nice round numbers.
Well, no. They are not certainly using
int, they might be using a more efficient data type.This might be for legacy reasons or it might be intentional because it might actually matter a lot. If I make up an example,
chat_participant_idis definitely stored with each message and probably also in some index, so you can search the messages. Multiply this over all chats on WhatsApp, even the ones with only two people in, and the difference betweenu8andu16might matter a lot.But I understand how a TypeScript or Java dev could think that the difference between 1 and 4 bytes is negligible.
But I understand how a TypeScript or Java dev could think that the difference between 1 and 4 bytes is negligible.
Shots fired.
All these tough guys think you can’t bit shift in Java, never worked on a project with more than two people. Many such cases.
Fair point, but still better than wasting a nuclear power plant worth of electricity to solve math homework with an LLM
They are not certainly using int
Probably why I said “almost certainly”. And I stand by that. We’re not talking about
chat_participant_id, we’re talking aboutGROUP_CHAT_LIMIT, probably a constant somewhere. And we’re talking about a value that would require a 9-bit unsigned int to store it, at a minimum (and therefore at least a 16-bit integer in sizes that actually exist for types). Unless it’s 8-bit and interprets a 0 as 256, which is highly unorthodox and would require bespoke coding basically all over instead of a basicnum <= GROUP_CHAT_LIMIT.Orrrr they have a u8 chat_participant_id of some kind and a binary data format for message passing. The GROUP_CHAT_LIMIT const may have a bigger data type, but they may very well be trying to conserve 3 bytes per message. Ids can easily start at 0.
150 gigs of bandwidth saved per day doesn’t seem like a whole lot at their scale, but if they archive all the metadata, that’s over 50 terabytes a year saved on storage - multiplied by how many copies they have of their data. Still not a lot tbh, but if they also conserve data in every other place they can, they could be saving petabytes per year in storage.
Still weird because then they’d have to reuse ids when people leave, otherwise you could join and leave 255 times to disable a group lol
And we’re talking about a value that would require a 9-bit unsigned int to store it, at a minimum (and therefore at least a 16-bit integer in sizes that actually exist for types). Unless it’s 8-bit and interprets a 0 as 256, which is highly unorthodox and would require bespoke coding basically all over instead of a basic
num <= GROUP_CHAT_LIMIT.I think you’re just very confused friend, or misunderstanding how binary counting works, because why in the 9 hells would they be using 9 bits (512 possible values) to store 8 bits (256 possible members) of data?
I think you’re confusing indexing (0-255) with counting (0-256), and mistakenly including a negation state (counting 0, which would be a null state for the variable) in your conception of the process. Because yes, index 255 is in fact count 256 and 0 would actually be 1. Index = count -1
I’m imagining something like this:
def add_member(group, user): if (len(group.members) <= GROUP_CHAT_LIMIT): ...If
GROUP_CHAT_LIMITis 8 bits, this does not work.So add a +1 like you would for any index to count comparison?
I guess I’m failing to see how this doesn’t work as long as you properly handle the comparison logic. Maybe you can explain how this doesn’t work…
It’ll have to do with packet headers, 8 bits is a lot for an instant message packet header.
For high volume wire formats using
uint8instead ofuint32can make a huge difference when considering the big picture. Not everyone is working on bootcamp level software.It’s not that they “like it”. It’s ultimately a hardware limitation. Of course we can have 64 bit integers, or however many bits. It’s an appealing optimization.
If each user is assigned a number as to where they’re placed in the group, I guess. But what happens when people are added and removed? If #145 leaves a full group, does #146 and beyond get decremented to make room for the new #256? (or #255 if zero-indexed). It just doesn’t seem like something you’d actually see in code not designed by a first semester CS student.
Also, more importantly, memory is cheap AF now 🤷♂️
While I completely agree with the sentiment, snorting too much “memory is cheap AF” could lead to terminal cases of Electron.
There would be no need to decrement later people because they’re definitely referred to using pointers. You’d just need to update the previous person’s pointer to the new next person.
If it’s a numeric ID (0-255) assigned to each person in the group, you’d either need to decrement later people or assign based on some kind of lowest available method, in which case you’d get kinda funny UX when new-member-Jerry can be #3 on the list because he’s taking over for old-member-Gerry, or he can be #255 because that’s the last spot.
If we’re talking about pointers, I assume you mean a collection with up to 256 of them. In which case, there are plenty of collection data structures out there that wouldn’t really have a hard limit (and if you go with a basic array, wouldn’t that have a size limit of far more than 256 natively on pretty much any language?)
Memory and network stop being cheap AF when you multiply it by a billion users. And Whatsapp is a mobile app that’s expected to work on the crappiest of networks and connections.
It is also used to transmit data including video. I don’t think an additional byte is noticeable on that kind of scale
when writing somewhat low-level code, you always make assumptions about things. in this case, they chose to manage 256 entries in some array; the bound used to be lower.
but implicitly there’s a tradeoff, probably memory / CPU utilisation in the server.
it’s always about the tradeoff between what the users want, what is easier for you to maintain, what your infrastructure can provide, etc.
There’s often a lot of fun cheats you can use - bitwise operators, etc - if your numbers are small powers of two.
Also it’s easier to organize memory, if you’re doing funky memory management tricks, if the memory you’re allocating fits nicely into the blocks available to you which are always in powers of two.
They’re not necessarily great reasons if you’re using a language with sufficient abstraction, but it’s still easier in most instances to use powers of two anyways if you’re getting into the guts of things.
The issue isn’t storing each individual ID, it’s all of the networking operations that are done and total things that are stored/cached per user in each chat. All of those things are handled and stored as efficiently as possible. Sure they could set it to any number, but 256 is a nice round one when considering everything that is happening and the use cases involved. They have user research data and probably see that 128 is too close to a group size that happens with some regularity, but group sizes very rarely get close to 256, and 512 is right out.
Maybe each user has a user id in a group, and that group user id is stored as 8bit int? Idk
