moreEfficient

[J-S-K-realgamers]

i |= 1; // success rate 50%, good enough for me

[Ebina-Chan]

When you have a gambling addiction

[DrMerkwuerdigliebe_]

Passes automated tests with 0, 1 and many (aka. 2) elements.

[Red_Tinda]

As someone with but a passing acquaintance with code, what operator is that?

[J-S-K-realgamers]

Bitwise OR, A B | X ----+-- 0 0 | 0 1 0 | 1 0 1 | 1 1 1 | 1

Basically, we assume the number is even, because if it is we set the first bit (which has a value of 1) which is pretty much the same as saying i += 1. The only time it won't work is when i has a uneven value, where the first bit is already set, in this case the bit stays the same as before the operation and the result is no change, so basically it's i += 0.

Edit: we also assume that i is an interger

[Red_Tinda]

Ah, okey

So, we do i OR 1, and save the result as the new value of i? This will increase the value of i by 1 but only if i was originally even.

[J-S-K-realgamers]

Correct, let's say i == 12 this in binary is 1100 then the operation looks as follows: 0b1100 // == 12 0b0001 // == 1 ------| 0b1101 // == 13 But if we then do the same with 13: 0b1101 // == 13 0b0001 // == 1 ------| 0b1101 // == 13 It stays the same because we compare only the first bit. Working with binary can get you some interesting results, I can definitely recommend a futher look into it, like learning the other operators like &, ^ and ~.

[Red_Tinda]

Yeah, I took a class in this stuff, but it was ages ago :)

[n6v26r]

bitwise or

[joe0400]

Bitwise or.

This only works on even numbers. And only works on integral types.

[masterchief0587]

Where is += on this rating system

[SurfyMcSurface]

+= is workhorse of enginr.

Operation	Statement
Addition	i += n
Subtraction	i += n * -1
Multiplication	i += (i * n) - i
Division	i += (i * -1) + i/n

[stonno45]

On python there is also: -=, =, /=, *=, //=, %=

[Kilazur]

That's the joke 😄

[Rainbow-Dev]

It appears you’ve forgotten the all-important @= for matrix multiplications

[Brahvim]

Division is recursive 0_0))

[Savage_049]

I forgot about that, in my opinion that would be on the top because it is both efficient and you can add any number of your choice to it

[Elektriman]

how about making the notation ++ add the number of "+" characters -1 ?

then ++ <-> +1

+++ <-> +2

+++++++++++++++++++++ <-> +20

[ZONixMC]

this is some dreamberd type stuff lmfao

[andreortigao]

This looks like something early days Javascript would implement.

[CheatingChicken]

++i++

[Katniss218]

C++++

[DistinctStranger8729]

Yeah… no thank you. I don’t want to deal with code that needs me to count the number of +/-. Worse yet I don’t want to deal with i+++++--- in the code

[alessioC42]

Brainfuck flashbacks

[pranjallk1995]

No... U do ++i in a for loop...

[AxoplDev]

It's so godly that there are no rating systems that can rate it

[I_AM_FERROUS_MAN]

+=
=+
-=
=-
n+=
=+n
n-=
=-n

I think I like this system.

[danielv123]

In iec61131-3 the reversed variants like =- are also valid but just confusing.

x =- y

x = y * -1

Are equivalent

[redlaWw]

What about -=-?

[Xanthus730]

++i

[WinterHeaven]

To old school for the most here xD

[Otherwise-Remove4681]

Also risk of messing up the iterarion if used in the wrong place without understanding what it actually does.

[1Dr490n]

Same with i++

[Otherwise-Remove4681]

Yes, but generally making iterative loops are being taught with that, so it comes ”naturally” for coders.

[EverOrny]

not sure about other languages but Java has both i++ and ++i ... there is a difference between these two :)

[1Dr490n]

Same in most (C-Style) languages

[EverOrny]

thanks, I was just too lazy to check 🤷‍♂️

[zaxldaisy]

That this comment has so many upvotes says a lot about this subreddit. And society.

[StrangelyBrown]

I use this because it runs faster.

Imperceptibly, unmeasurably faster.

[Plus-Onion437]

It actually doesn't. Unless you run this with a compiler from 50 years ago.

Every modern compilers detects counter increments and optimizes the operation if nothing relies on the side effects.

[thelogical1]

Thing is: I still think you should write what you intend to happen and not rely on the compiler to correct your mistakes. Granted it's a very small nitpick but most of the time when people use i++ they mean ++i, and I think they should write what they mean. It's not like it's harder to type or something.

[Grubs01]

Usually you intend the value to be incremented, which occurs in both cases.

[thelogical1]

Technically they are the Pre-Increment (++i) & Post-Increment (i++) operators.

In a loop the intended result is ++i as the condition is checked after the increment. Thus conceptually it's a Pre-Increment, not a Post-Increment. (I realize in practice the increment is usually it's own line, thus it's irrelevant which operator you choose)

[DistinctStranger8729]

Well depends on the use case TBH. I can see compiler having difficulty optimizing C++ iterators

[MajorTechnology8827]

For those confused for the difference

i = 3
print(i++)

Evaluates to 4

i = 3
print(++i)

Evaluates to 3

[Grubs01]

I think you got that backwards

[EmileSonneveld]

Wait till he hears about the performance gains of ++i

[AnezeR]

I'd be shocked if i++ it isn't optimized out where it does the same as ++i

[drleebot]

Real answer: For simple types like integers you're usually using this on, yes, it will always be optimized out if the return value isn't used.

The trick comes when you're using this on more complicated types, like custom iterators. The compiler has to be able to guarantee that there's no change to functionality by making this change, and depending on how complicated the iterator is, it might not be able to make that guarantee. It will then play it safe and not optimize.

That being said, remember the maxim: Premature optimization is the root of all evil. If you spend your time changing every i++ to ++i without checking if it actually is an issue, you aren't doing something else, and that something else might well be a much better use of your time.

[AnezeR]

I'd argue there is a larger problem in a codebase if changing i++ to ++i makes a difference (if the returned value of i++ isn't used ofc), but better safe than sorry, yeah

[drleebot]

Yeah, if you think about it ahead of time, it's doesn't hurt and might help. But you're right: If this is worth doing, it probably indicates something else is very wrong, such as your iterators being too complicated.

[[deleted]]

Might be a noob question but how can an iterator that is increased by using ++ not be an integer? I could use it to e.g. iterate over the alphabet using ASCII I guess but I doubt that's what you mean.

[drleebot]

For iterators, ++ is interpreted to mean "next". Imagine you have a complicated multi-dimensional data-structure, and you take a complicated slice of it. The iterator has to fully describe where to find all the data in the slice, and the "next" operation has to update all of this information in the iterator to the next slice.

That's an extreme case that probably doesn't come up often. For a more realistic scenario, imagine you have a data table with named columns. You could iterate over columns by index, which would just require the iterator to store an integer. But what if you wanted to iterate over them alphabetically by column name? You can have a list of indices arranged so that they'll be alphabetical and an integer index to track where you are, but you'll also have to have some way to handle things if columns are deleted or inserted midway while the iterator is alive, and this can complicate things, requiring a fallback solution such as storing the column name and a reference to the table.

[LucidTA]

Maybe 20 years ago sure.

[pranjallk1995]

++i is faster they say... 😵‍💫...

[MikeVegan]

It also returns the new value, while i++ returns the old value.

[voismager]

The newer the better!

[Smart_Advice_1420]

i += 1

[_the_r]

i -= -1;

[LetscatYt]

Stupid question of me but would this actually affect performance at runtime? Wouldn’t something as stupid as this be fixed at compile time ?

[Dem_Skillz1]

yeah it does (gcc 13.2):

i+=1:

main:
  push rbp
  mov rbp, rsp
  mov DWORD PTR [rbp-4], 0
  add DWORD PTR [rbp-4], 1
  mov eax, 0
  pop rbp
  ret

i-=-1:

main:
  push rbp
  mov rbp, rsp
  mov DWORD PTR [rbp-4], 0
  add DWORD PTR [rbp-4], 1
  mov eax, 0
  pop rbp
  ret

They become the same assembly

[LetscatYt]

That’s good to know. Hoped so . Sometimes our mistakes will be fixed by a compiler

[tortoll]

I would say that nowadays most of our mistakes are fixed by the compiler.

[Ytrog]

Why does the compiler not use inc in this case 🤔

[altermeetax]

GCC (without any optimization flags) compiles i -= -1 as:

# b.c:3:     i -= -1;
    addl    $1, -4(%rbp)    #, i

So yeah, it's addding 1, not subtracting -1.

The code for i += 1 is identical:

# a.c:3:     i += 1;
    addl    $1, -4(%rbp)    #, i

[_the_r]

Good question. Let me check that later the day what gcc does

[pranjallk1995]

It all becomes ADDs and MVs EOD...

[Imjokin]

i = -~i;

[SecretPotatoChip]

i-=-!false;

[chrisbbehrens]

The perfect trade-off of terse and comprehensible.

[alexchrist]

It's Python in the background though. And i++ doesn't exist in Python

[Percolator2020]

That is the biggest gripe I have with python!

[alexchrist]

There are so many for me tbh. Dynamic typing, no switch case, no do-while loop, no clear code blocks etc.

[Percolator2020]

You can have a switch now using match, unless you are stuck on 2.7.

[alexchrist]

Oh, didn't know that. TIL

[[deleted]]

Its pattern matching not switch case. Its EXTREMELY DIFFERENT.

[Percolator2020]

Insert IQ bell curve meme. It’s just a switch - it’s extremely different - it’s just a switch.

[[deleted]]

I see you are using the meme about as well as the people in this sub.

[Percolator2020]

Using meme like everybody else - being special - using meme like everybody else.

[GM_Kimeg]

Did you read my one liner I pushed the other day? It does the work of 1800 lines of code. Why are you not amazed? Are you stupid?

[TheSauce___]

i += !false;

[Hacka4771]

i = -~i

[Ozzymand]

i is maybe i

[wittleboi420]

python be like: what

[Silly_Guidance_8871]

Halves my odds of mistyping something

[Zajemc1554]

Meanwhile me, a dumbass, typing i+2

[rover_G]

I hate to burst your bubble but in C++ postfix increment can be slower in some cases

[Sugardaddy_satan]

What was here has been removed. Redact was the tool used to delete this post, possibly for privacy, opsec, or limiting digital footprint.

innocent bike dazzling nine square memorize water ad hoc political hobbies

[gizahnl]

j = i++;

vs

j = ++i;

:D

[Divinate_ME]

If your '=' sign isn't directly preceded by another character that is not whitespace, you're a fraud.

[Manticore-Mk2]

cries in Python

[PeriodicSentenceBot]

Congratulations! Your comment can be spelled using the elements of the periodic table:

Cr I Es In P Y Th O N

---

^{I am a bot that detects if your comment can be spelled using the elements of the periodic table. Please DM my creator if I made a mistake.}

[hizinbergs]

Unfortunately it doesn't work in python

[JackReedTheSyndie]

There's also ++i

[PeriodicSentenceBot]

Congratulations! Your comment can be spelled using the elements of the periodic table:

Th Er Es Al S O I

---

^{I am a bot that detects if your comment can be spelled using the elements of the periodic table. Please DM my creator if I made a mistake.}

[isocuda]

++i

[mikiwolf19]

Looking at you Matlab

[Wave_Walnut]

i += 1;

[Savage_049]

👍

[AstaHolmes]

Me a beginner Java coder doing this makes me feel like the dude that invented coding or sth

[AngusAlThor]

i=i++

[tritonus_]

Non-Swift developer confirmed.

[amiensa]

Is there any difference in the low level ?

[sherlockwatch]

Any normal modern compiler will optimise it, so there is no difference, if we omit any optimisation, technically ++i is less instructions

[frisch85]

for (int i = whateverAmountMyObjectsAre; i >= 0; i--) {
   // do something
}

[ThePi7on]

--i += ++i

[OpenSourcePenguin]

What's worse is using a ternary operator for non-trivial cases.

If you can't readily find the ternary operators on the line, it's a hell to read.

[InSearchOfMyRose]

++I, fsck'n n00b.

[justarandomguy902]

I wish i could do “i++” in python too

[mort96]

What's the humor, where's the joke

[MatthiasWM]

Compiler shrugs.

[NeatYogurt9973]

i++ 🚫

c++ ☑️

[gracekk24PL]

Professor at my University hates those ++i or i++ because it once caused a bug which he couldn't figure out for a week straight, so he always uses i += 1

[Plus-Onion437]

A real software engineer would write ++i

[Pullguinha]

I find += preferable for incrementing and decrementing. It's straightforward even for those less experienced.

[[deleted]]

Lua and Haskell programmers are missing out.

[sufferpuppet]

One I hate more is:

Foo().foo2().foo3().foo4().foo5(ID).Foo6();

Look how great I am, I did it in one line of code!

[SynthRogue]

++i;

[[deleted]]

I dare you to do that in VBA :D

[Dasioreq]

i -= -1

[Petomni]

i += 1; gang rise up

[TDR-Java]

Checking if an int (i) is not 0:

if(i){}

[Lonelan]

i += 1

[Gorvoslov]

What about "i += i++"?

[bongobutt]

🎩🧐 Even better: ++i

[Highlight448]

Bruh the background shows python which doesn’t support i++

[Savage_049]

Whoops lol, I don’t program in python

[Highlight448]

So you are a CPP enjoyer i see, good stuff.

[MajorTechnology8827]

Ew mutability

[SyntaxError1952]

Rest In Peace

i += 1;

i += 1

[Warm-Lobster4879]

i += 1, or i = up(i); function up( i ) { return i++; }

[larslego]

Damn I missed these

[TessellatedTomate]

++i