Unused variables

Sjmarf@sh.itjust.works to Programmer Humor@programming.dev – 872 points –
51

But are you gonna return something for this method??? You said you'd return an integer, yet there is no return statement!

and it had better be an integer! it had better be an integer, motherfucker!!

Well yea... If you write "return " that is actually wrong, as opposed to just not having gotten around to filling it in yet

This is why I always write my methods from bottom to top. This way I've always got a return statement and I use my variables before they are even declared.

For a second there I thought you might be serious

I do actually use variables before I declare them most of the time. IDEs make it so easy to then generate the declaration with the correct type.

That’s true, in fact I’ve started doing that myself. Same with methods, instead of going and writing the method and then coming back to use it, I’ll write the invocation first.

IDE is one thing, Go refuses to compile. Like calm down, I'm going to use it in a second. Just let me test the basics of my new method before I start using this variable.

Or every time you add or remove a printf it refuses to compile until you remove that unused import. Please just fuck off.

Yeah I think it's trauma due to C/C++'s awful warning system, where you need a gazillion warnings for all the flaws in the language but because there are a gazillion of them and some are quite noisy and false positives prone, it's extremely common to ignore them. Even worse, even the deadly no-brainer ones (e.g. not returning something from a function that says it will) tend to be off by default, which means it is common to release code that triggers some warnings.

Finally C/C++ doesn't have a good packaging story so you'll pretty much always see warnings from third party code in your compilations, leading you to ignore warnings even more.

Based on that, it's very easy to see why the Go people said "no warnings!". An unused variable should definitely be at least a warning so they have no choice but to make it an error.

I think Rust has proven that it was the wrong decision though. When you have proper packaging support (as Go does), it's trivial to suppress warnings in third party code, and so people don't ignore warnings. Also it's a modern language so you don't need to warn for the mistakes the language made (like case fall through, octal literals) because hopefully you didn't make any (or at least as many).

VSCode with Go language support: removes unused variable on save "Fixed that compilation bug for ya, boss"

Like actually deletes them from the working copy? Or just removes them in the code sent to the compiler but they still appear in the editor?

Yeah IIRC it deletes them, which is as mad as you would expect. Maybe they've fixed that since I used it last which was some years ago.

Compiler/interpreter: Can't find variable farfignewton.

Earlier:

Me: Declare variables near, far

IDE: Oh! You mean farfignewton right? I found that in some completely unrelated library you didn't write. Allow me complete that for you while you're not paying attention.

And people wonder why I stick to Vim.

I mean, if you want something dumb you can use any text editor.

Yes, compared to the annoyances of "smart" IDEs, I do want something dumb.

No I'm good with smart IDEs. Anyway don't people set up Vim as practically an IDE these days anyway? That's what Vim users always tell me.

The advantage there is that you pick and choose how you turn things on, so you leave out the annoying bits.

One thing most text editors can do is print. I was shocked the other day when I couldn't print a readme from vscode when someone asked for hard copy.

Print?

Why would you ever need to print?

Because some of us are bitter at the trees for generating so much pollen at this time of year and want revenge.

That's fair, I didn't think of that.

using lsp in vim has pretty much the same problem especially with java

near, far

The obvious autocomplete is , wherever you are

This is why I fear activating any AI features in the IDE.

thank you for flooding my memory with a bunch of silly 90s car commercials

I try my best to make my IDEs follow the principal that I should be able to type without looking at the screen, but apparently IDEs are really invested in return accepting completions to the point it's often not configurable even when every other key is.

Visual Studio: PROPERTY DOESN'T EXIST ON TYPE!! NOTHING EXISTS ANYMORE!!!!!! REALITY HAS COLLAPSED!

Me: What? I haven't even touched that class, let me check.

Visual Studio: Oops, nevermind, héhé 🙃

I swear to god this didnt used to be a problem few years ago. However im having that bug constantly now...

Me:

jetbrains: This heredoc goes on FOREVER!

Me: I'm going to close it..

jetbrains:

Imagine lint running on format and your linter removing unused variables: you start typing, hit format by muscle memory before using the variable. Rinse and repeat.

I start writing the implementation and get the "variable not defined" error and then let the ide add the declaration. It's less keys to press and misspell.

I recently started poking with Vue, For the most part when it comes to webapps I've mostly worked with React, Blazor, and a touch of Svelte. The linter is so aggressive. I start defining a method and it instantly goes "IT DOESN'T RETURN ANYTHING!!"

Okay, thanks! I literally just defined the return type!

Word proccessors have had this figured out for ages, I wonder why it's so hard to implement this QoL change for code

How do you mean? You can't type a word without using it in a word processor. Once the word is typed out it's been used. Variables need to be declared then used so 2 separate steps.

There's no direct equivalent but word like won't bother me about spelling or grammar until I'm done typing that part

What do you mean? Variables do not necessarily need to be used, you can allocate memory for some value and initialise it but then simply don't do anything with it.

You can but compilers will optimise that away unless you tell it not to.

Meanwhile go: you will remove it or I won't compile, unless you know the secret handshake

Yes you can but the little red squiggles show in your editor to warn you that it's unused code. That's what the whole post is about lol

I'm not a CS major but why exactly does having a variable or parameter that's not used in C, C# and C++ throw a warning

It's probably gonna be optimized out by the compiler. However, linters will mark it for you, since it suggests that you actually wanted to do something with that variable and forgot about it after declaration.

... Or it can be removed to reduce visual noise once it's not necessary anymore after refactoring.

Lets say you use a variable named abcd in your function. And a variable named abcb in a for loop inside the same function. But because reasons you mistakenly use abcd inside that loop and modify the wrong variable, so that your code sometimes doesnt work properly.

It's to prevent mistakes like that.

A similar thing is to use const when the variable is not modified.

Because it's code that literally doesn't do anything. Some languages won't even let you compile without special instructions.