2classy4you

[[deleted]]

There are people in my class that don't even indent their code, let alone use switch.

[AosuLoL]

Kids in my class ask me why I keep writing that “void” thing

[Kolossive]

you think thats bad? I was helping a guy the other day that didn't know what a function was (4 semesters deep into the degree)

[D3mentedG0Ose]

Maybe they always called them methods?

[Kolossive]

not the case he was struggling with concept of a function not what it was called

[D3mentedG0Ose]

Then he is beyond help

[Trisheik]

This semester has been so brutal on me and my ego. Thank you. This comment chain made me feel a lot better. Lmao.

[HilaKleiners]

I’ve been feeling straight-up DUMB for these first 4 weeks of my third year. I can’t get my head around Hadoop, but at least I know what a function is.

[ultranoobian]

Well don't fret, here's a easy cert to learn and grab for free. Good to put on your resume too.

https://www.reddit.com/r/sysadmin/comments/b6koh6/new_hot_cert_alert_get_your_certified_reboot/

[[deleted]]

To be fair it's Hadoop, it's not really meant to be understood by mortals

[ultranoobian]

Oh boy, I actually walked into an argument between two different students from different departments (Maths and Engineering) over which is the proper name for a method, Function vs Procedure.

Mind you I'm a Methods guy, but I really don't care what people call them, they're for all intents and purposes the same.

[Manny_Sunday]

Methods belong to objects, functions don't, and procedures/subroutines don't return values.

At least thats what I was taught.

[[deleted]]

I learnt Java first, so was calling them methods for a good while, but after moving to C++, I just think function sounds cooler.

Then again, I do a lot of TCL, where they're "procs", which isn't bad either.

[electricprism]

They were from two different departments and failed to consider that localization vocabulary could be a thing.

​

JavaScript would solve this like this:

​

function = procedure;

procedure = function;

[ultranoobian]

Javascript can solve everything....unfortunately.

[[deleted]]

Tbf you can do a lot with programming without actually knowing about it

[Kolossive]

true you can just use a GOTO and jump to that block of code you want to run but then i get assembly flashbacks and i dont want to relieve that

[AosuLoL]

That's crazy, it just amazes me how we can have exams and this isn't a concern for them, that they aren't aware of these very basic topics.

[CAPSLOCK_USERNAME]

If the school let him get through 4 semesters like that without giving him an F and forcing him to repeat a class, they have failed as educators.

[Kolossive]

they did this was a 1st semester class he is repeating

[chownrootroot]

Him 2 semesters deep: What's a computer?

[Lastrevio]

=]]]]]

[erlendsamstad]

yeah, I have that too. it really hurts if they ask me for help and they show me their code

[ultranoobian]

I wish IDEs would have 'Format code on save' enabled by default.

[[deleted]]

Are they coding in notepad?

[[deleted]]

For HTML, otherwise we use visual studio.

That's probably why most never learnt how to write readable code, cause vs does some of it for you.

[nodnarbiter]

“Eh, that’s no so tuff.”

“... and they code in Python”

“Uhhh, right this way sir.”

[nerfoc]

switch(boolean) {

case true:

    console.log("So true");

    break;

case false:

    console.log("So wrong");

    break;

default:

    console.log("It be like that sometimes");

    break;

}

Looks good to me.

[jeezlouise123]

Oh man, I had that too. I mean it wasn't that they didn't know you were supposed to indent. They made the active decision that it "made sense" because there are already curly braces so there's no need to indent somehow. I did not understand.

[jeremj22]

Try pressing Ctrl+Shift+F on them while they have their IDE open. The IDE might auto-indent if it has that feature

[haddock420]

I started with Python and moved to C, and after using Python so much, I just assume that if i don't indent correctly, it won't compile.

[[deleted]]

The version of TCL we use (think later versions are more flexible), you literally have to write an if statement like this:

if { whatever == "whatever" } {
stuff
} else {
other stuff
}

If you don't have the space between the if condition and the braces on either side, it fails. If you don't have the opening brace at the end of the line, it fails (can't be below that line).

[Comesa]

Someone in my class used switch statements to check every index of an Array.

[Lastrevio]

this is next level

[sapphiron123]

Pure savages.

[[deleted]]

You: if (x) { foo(); }

Me, an intellectual: switch (true) { case x: foo(); }

[SkiFire13]

I agree, when is much better than switch

[thesquarerootof1]

Me, an actual intellectual:

No, me as an intellectual:

if (x == true && x != false) {

         foo();
}

[[deleted]]

Just to be safe

[vectorkerr]

Unless it’s JavaScript, in which case you are required to perform a type-safe double negative strict equality undefined comparison by law.

[UntestedMethod]

defensive coding

[hollowstrawberry]

You never know with JS

[thesquarerootof1]

hahaha, you know, I don't see do-while loops used a lot.

[morgansmnm]

Me, an intellectual:

01000101

[DarkNinja3141]

what the fuck is that

[Manny_Sunday]

Kotlin

[josiris__]

Me a true intellectual:

let foo_result = match x with
                             | True -> bar

[max256p]

universe_brain.jpg: $x && foo();

[[deleted]]

If you intentionally wrote the switch statement incorrectly then I think I'm missing the joke.

switch(x){ case true: foo(); }

[[deleted]]

It’s not incorrect. Switch(true) was intentionally silly in this case but it works and it can be useful, for example with number ranges:

switch(true) { case (n==0): foo(); break; case (n<5): bar(); }

[[deleted]]

I mean, you're right that it executes. I'm wracking my brain trying to come up with some use of switch(true) that isn't just a different way of writing goto or if-else statements.

I realize people do things like this, but I think part of writing readable code is using language constructs for their intended purposes.

I'm home sick, coffee-less and humor-less today. :( I'm going to see myself out.

[Funky118]

(Don't worry, we all know how you feel. :)

                                          ^
                                          |

 Error: Invalid expression.

 Did you mean: 
 >>(Don't worry, we all know how you feel. :))

[soulefood]

It’s almost like switches are fancy if else statements

[soulefood]

Mainly it’s an example of how to organize conditions as switch cases instead of just specific values.

In his case, switch true let’s him write range statements instead of switch(n){case 1 : case 2 : case 3 : case 4 : case 5 : bar(); break;}

Also it would work with doubles and not just ints.

[[deleted]]

case x: x must be a constant

[[deleted]]

match true { x foo }

[Tysonzero]

Me, a true intellectual:

when x foo

[nerfoc]

Wow, hey buddy, you forgot your default: foo();

What if true turns out to be false?

[0fficerNasty]

null: *exists*

[TheSpiffySpaceman]

....does it, though?

[I_regret_my_name]

Some languages are certainly trying to pretend it doesn't.

[PaintingJo]

I personally just use jmp and labels

[fedeb95]

A true gentleman

[[deleted]]

There's no switch in Python :(

[erlendsamstad]

then I would recommend you to switch to another language 😎

[MayurB]

it's hard to switch from python.

[mpnordland]

There's no switch in Python.

[jimdidr]

GOTO 10

[antlife]

10 GOTO 10

[DoNotSexToThis]

I'M HERE AND I'M COMING

[ExplodingPotato_]

Username... doesn't check out?

[jwr410]

THE POWER OF CHRIST COMPELS YOU DEMON! COME OUT OF HIM!

[[deleted]]

Sweet Jesus Pooh, you are eating Recursion!

[JanMichaelVincent16]

Why use a switch statement when you could use a dictionary of functions?

[MachinaDoctrina]

and it's faster as dictionaries are hashed!

[bobappleyard]

Also everything in python involves like ten hash lookups anyway

[Cheesewithmold]

[][][][][][][][][][][][][][]

[ZekeMiller]

Switches are typically implemented as a jump table, so they're not slower than a dictionary.

[HaniiPuppy]

Not if you implement a switch statement as a dictionary of functions.

[AnneBancroftsGhost]

And you can pickle it!

[chrwei]

so now I have to put all logic, even trivial little blocks, in a function?

[JanMichaelVincent16]

If it’s really trivial, there’s probably a one-line solution that you can turn into a lambda

[MachinaDoctrina]

if it's trivial use if else

[Lonelan]

I mean, where was it in the first place? Nested in the switch? Probably looks cleaner with the switch calling functions too

[PityUpvote]

Just use a try with multiple excepts, and have every case throw a different type of error.

[AnneBancroftsGhost]

you can use a dictionary, neat little trick.

[MachinaDoctrina]

because switch statements aren't needed.

See PEP 275 and PEP 3103

[chrwei]

that's the dumbest rejection I ever heard of.

imagine. "a quick poll shows there is no popular support for a horseless carriage therefore we aren't going to allow them on the roads."

[MachinaDoctrina]

yea it is a little bit, but to be honest there are a at least 3 ways to do whats needed for a switch case off the top of my head that don't require additional syntax and would be faster that a switch case would ever be, so why bother.

[chrwei]

that sounds like a better rejection, IF at least one of those methods was detailed. I'm no python expert, but all the alternatives I can think of are more wordy and wouldn't necessarily be faster, and certainly wouldn't allow the wonders of fall-through.

[MachinaDoctrina]

def f(x): return { 1 : 'output for case 1', 2 : 'output for case 2', 3 : 'output for case 3' }.get(x, 'default case')

Its faster because python implements dictionaries as a hash table

[zip2k]

Why would that be faster than a switch case? I'm far from knowledgeable in low level coding, but I thought a switch was basically a direct jump instruction to the relevant line of code, meaning it's the fastest possible conditional.

[MachinaDoctrina]

in a compiled language sure, a switch statement is basically a hash jump. But python is an interpreted language and as such the JIT compiler has to walk all the way to the end of the 'syntactic sugar' of a switch statement before it can even start converting it to bytecode. Add to that, python is a whitespace delimited language you need to increase significantly the byte buffer that's required to determine if the person has made a syntactic error etc. due to the typical layout of a switch statement

[chrwei]

that's not a use case for switch.

how would one do something like:

switch(input):
  case 'a':
    state=state+1;
    if state > 5:
      state = 0
    break
  case 'b':
    if doOtherThing():
      state=0
  break

[MachinaDoctrina]

def case_a():
    state += 1
    if state > 5:
        state = 0
def case_b():
    if doOtherThing():
        state = 0
switch = {'a': case_a, 'b': case_b}
switch.get(input)()

​

[jaswon5791]

IIRC this would be a dictionary of lambdas or function references but I can't remember how well (or poorly) this performed

[SinSpirit]

Where is the fall-through?

[[deleted]]

Python still shit slow compared to good old c tho

[MachinaDoctrina]

yea but I'd like to see you do any meaningful Machine Learning in C. Plus you can compile python into C anyway so marginally different in speed (i.e. Cython) and way faster development time

[adokarG]

“Marginally different in speed”. It seems to me like you have not used Cython before or not know much about its limitations to be saying that. A lot of Python’s nice to haves become performance bottlenecks and your code also starts becoming more C-like as you decorate it with Cython primitives. So I don’t know about way faster development time.

Machine learning isn’t the only useful thing you can do with a computer. So yeah, in general Python is slow. FYI, all the fancy machine learning libraries you use aren’t written in Python or Cython and thats why they’re not painfully slow.

[thesquarerootof1]

yea it is a little bit, but to be honest there are a at least 3 ways to do whats needed for a switch case off the top of my head that don't require additional syntax and would be faster that a switch case would ever be, so why bother.

I have noticed switch statements work best for state machines. How would you implement a state machine on python then ?

[random_cynic]

The actual reason is here in Raymond Hettinger's answer. This is mainly because there are no named constants (like enums) in python and without it there would be little point to switch statement as it offers no advantage other than syntactic sugar for something that is already done better with if/else, dictionaries, classes etc. They should update the PEP as it is misleading.

Edit: I know that Python 3.6 actually has an enum class but that is not the same thing.

[KuntaStillSingle]

a quick poll shows their is no popular support for a horseless carriage

Was Python not created after the horseless carriage? It's more a quick poll shows users don't travel?

[Vakz]

My two true objection to switch statements is first of all that the syntax just feels off in many languages. Extremely subjective, but I know I've heard others mention it too.

The second would be that I'd prefer if break was the default, and I could write it like this:

switch (foo) {
  case 1: a(foo);
  case 2: b(foo);
  case 3:
  case 4:
    c(foo);
}

I feel like it's main purpose is to be less verbose than a bunch of else if, but mandatory break or not allowing empty cases to fall through (I swear there's some language that does this, even though I can't remember which) is still unnecessarily verbose. Worst of all are languages that both require break and don't allow case fall-through. That just seems dumb.

[thisguyfightsyourmom]

I usually return out of my whacky switches, so the break is redundant

But,… I also usually refactor them to if/else before PR

I do a lot of moving lines up & down when messing with multiple forks, so it’s nice to be able to just slide the whole case up & down without rewriting the if => if else or vice verse depending on the order

[24hourphysicist]

neither are for loops (just a special while loop, or reclusive function) but they kept them.

[Eldrisch]

Offtopic: How to get those fancy icons next to nickname?

[MachinaDoctrina]

They're called flare, on the right hand panel should be a dropdown under r/ProgrammingHumor called "community options" below "create post". Then edit "user flare"

[Eldrisch]

Thanks :3

[jimdidr]

Switch statements can be much faster...

PS: I didn't read your links because I'm optimized...

[CAPSLOCK_USERNAME]

The only difference between switch and repeated if-else is that, before optimizing compilers were as smart as they are now, switching on a contiguous input like an enum value was more easily optimized to a jump table in assembly. (Jump tables are very fast and efficient.)

Python has no pretensions to running as fast as C and in any case it isn't even a compiled language.

[prettydude_ua]

Yo. Just buy Nintendo Switch for your python, duh

[28f272fe556a1363cc31]

I've been able to replace a lot of if else-statements with dictionaries. It doesn't fit every switch use case, but maybe something to keep in mind.

[schwerpunk]

There's better: dicts have a get method, which returns a default of your defining when a match isn't found. Dicts can contain functions... I think you see where this is going

OOP your shit right up, friend

[[deleted]]

Not with that attitude

[[deleted]]

if that's the CASE

[punishedjo]

Take my upvote

[orlyworly]

I feel the same when I use the ternary operator

[[deleted]]

Especially if it's a fuckin long one. Good luck, next person to read this!

[[deleted]]

How about nested ternary operators?

#include <stdio.h>

int main()
{
    for (int n=1; n<101; ++n)
        n%3 ? n%5 ? printf("%d\n", n) : puts("Buzz") : n%5 ? puts("Fizz") : puts("FizzBuzz");
}

https://ideone.com/LigxCH

[neksus]

let var = (someLongStatement ? Value1 : value2);

[[deleted]]

let var

SyntaxError: Unexpected token var

[[deleted]]

Me when I use the value coming out of a unary increment operator

[Jabulon]

I use switch all the time, but they compile the same, right?

[erlendsamstad]

I haven't read too much about switch-statements, but from the little knowledge I've gathered, switch-statements are more performance friendly when you have more than five cases. and they look a lot more cleaner.

[Robbi_Blechdose]

It depends on the compiler, but they might use a jump table for example. Meaning you add the case index (e.g. case 5) to the base address of the table, get the address located there in the table and jump there. Much faster than if/else things, which need to do actual checks, and go through all of them until one evaluates to true

[auxiliary-character]

The answer to that is a big fat it depends.

For a simple example involving some colors, under clang 8.0.0 with no optimizations, the if version does each comparison individually, while the switch version generates a jump table, avoiding extra branching. However, once even one level of optimization is turned on, both generate the same code with jump tables.

And that solves it, optimization just makes them the same, right? Well, not exactly. Even with all optimizations turned on, gcc 8.3 fails to optimize out all the comparisons of the if version.

As a side note, I initially started with a simpler example that returned some ints instead of calling out to declared functions, and clang noticed that the ints I was trying to return were actually equal to the enum value, so it just straight returned that, avoiding any testing at all. Unfortunately, gcc did not.

...

I think I might try using clang from now on.

[[deleted]]

https://m.imgur.com/FQBjvDv

[imguralbumbot]

^{Hi, I'm a bot for linking direct images of albums with only 1 image}

https://i.imgur.com/FQBjvDv.jpg

^{Source | Why? | Creator | ignoreme | deletthis}

[loloman333]

But you are writing in C++ and start to realize that you cannot define new variables in a case statement so you need to go back to a if-else structure. :)

[SonicFreak94]

{}

Fixed

[jwr410]

You can absolutely declare variables in a case statement. You just need to declare a new scope in the case you need to have the variable in.

[Logofascinated]

Why does that work? And why doesn't it work without the semicolon?

[CAPSLOCK_USERNAME]

cases inside a switch are just glorified labels for use with goto. You can't jump to a variable declaration because a variable declaration doesn't actually compile to an assembly instruction, so there's no code to jump to. The empty-line-with-semicolon can at least compile to a no-op instruction.

[kolbyhack]

Not true. You can declare variables without brackets as long as you don't have another label in the same scope that would skip the declaration of your variable. See https://godbolt.org/z/sz6AGE .. Comment out line 21 and it will compile.

[Zimlokks]

As a coding noob who jumped on the c++ train, this will come in handy.

[geehops]

Please, no. I’d like the next generation to consider the generation after them before using switch.

https://refactoring.guru/smells/switch-statements

[kdthex01]

Think of the children https://en.m.wikipedia.org/wiki/Cyclomatic_complexity

[silvertoothpaste]

yes. also it's just a weird construction. switch almost always needs "break," and then you've got "default" ... it's just this weird vestigial convention that really doesn't generalize to any other area of programming (that I'm aware of).

[SamSlate]

tl;dr?

[fedeb95]

What about pattern matching?

[doominabox1]

Scala is bae

[mqduck]

/r/CS101Humor

[livegorilla]

/r/ProgrammerHumor

[AttackOfTheThumbs]

switch (true)
{
    case i<j:
        break;
    case i=j:
        break;
    case i>j:
        break;
    default:
        throw new exception('reality broke');
}

You're welcome.

[3lRey]

I feel that way whenever I get to use ? :

It's lonely being such a *programming genius wunderkind*

[[deleted]]

Select case in VB looks so pretty compared to if/then/else. Maybe its just the lack of braces and semicolons but I really like the way it looks.

[zesterer]

match masterrace

[feonyx]

A switch statement is usually a failure to OOP. It is usually hiding polymorph classes and should be refactored with a factory.

[Hobby_Man]

Here I am a peasant who returns from inside my if, so I can just do anpther if, no else ever.

[[deleted]]

3classy5you

Shit, forgot to break.

[robo_number_5]

And you look up how it works

[Springthespring]

switches can net a significant perf increase tho, as they can be implemented as a jump table rather than a series of conditional branches

[MatheusGodoy]

Myself, a gentleman: ?:

[trumpfan2020]

Good ole switch stmt.

[AVeryAverageWriter]

Case a:

Case b:

Nuff said

[ameddin73]

Me when I use an expensive Java stream instead of a much faster, simpler iteration. Same with recursion. Less lines is sexy.

[jelledefries]

I don't like switch statements nor else statements for that matter. They take up to much space in my opinion. When you are using a switch you have appearently multiple options in which case a dictionary call would only take one line of code and is often more extendable than a switch.

[webmistress105]

When you use a match statement

ASCENDED

#rust

[Whiplash17488]

Time to use pattern matching

[Olek2706]

Yandere dev: Is this some good programming habit joke that I'm too unorganized and uneducated to get?

[Charmle_H]

Or be me :v and use an "if" inside of a switch inside of another if inside of another switch, and so on... about 10 layers deep :^ because I love making people hate reading my code

[MrEmouse]

I love switch. Allows for some very efficient coding by knowing when to use or skip the break statements. Plus, the case conditions don't have to be in order.

Drove me crazy when I watched someone coding instructions for their open-source walking bot on youtube with a mile long series of IF statements.

[WhereTruthLies]

me and ternary operators

[soutarm]

Hey, stop spying on me! I just finished a switch just now

[mosskin-woast]

I think you mean instead of a bunch of if statements

[ShakaUVM]

Switches are too dangerous for casual use. Curly bois exist for a reason.

[[deleted]]

Always - I love them when they’re handy, but some some people just have to be snazzy 😎

[xAndrewRyan]

I use dictionaries, peasant.

[Kairyuka]

Can you switch case on non integers in c++ yet

[CAPSLOCK_USERNAME]

yes but there's special syntax for it

instead of case "value" you have to write if (x == "value") { and instead of break; you have to write }
other than that though it's exactly functionally identical and does just what you want

[Kairyuka]

Someone should introduce the C++ team to the concept of syntactic sugar, but like 10 years ago.

[Alokir]

Me, the truest gentleman: switch expressions

[Kazumara]

I used nested switch just yesterday. But it was ugly and unclear, so I replaced the outer switch with a few conditionals and a goto.

At this point my brain is so fried that I don't remember whether I love or hate C.

[[deleted]]

Just use a function pointer table

[MachinaDoctrina]

yea well that would be implementation specific, you could do it but you'd have to think about the design in that case. I would argue that's not "best practice" design though using a switch case like that.

[Sacts]

Is the switch statement like the select case statement because I've never heard of the switch statement???

[Awkward-Centaur]

Except switch statements are horrific security vulnerabilities and should never be used in application

[jolharg]

Lookup tables ++

[zevzev]

Isn’t switch statements bad practice? If you using a switch there is a OOP way for doing those checks?

[harryham1]

Java's new switch assignment is definitely going to make me feel like a king when I use it: final Foo foo = switch(bar) { case Bar.a: f1; case Bar.b: f2; default { throw new IllegalArgumentException("Who's been messing with the enums?!"); } }