The world's two worst variable names

http://www.oreillynet.com/onlamp/blog/2004/03/the_worlds_two_worst_variable.html

by niyazpk • 16 years ago

31 40 16 years ago

allend• 16 years ago

I don't know if $data is the 'worst'. I've used 'int nothing', and 'int anything' before.

_b8r0• 16 years ago

Oh thank god it's not the stuff I use. My code is so bad that every time I declare a variable a fairy dies. At least there's something I'm not doing wrong.

prog• 16 years ago

While programming in C I use str quite a bit. Moving to Python, that conflicts with the str builtin function, so I now use s.

etherael• 16 years ago

foo & bar

nailer5• 16 years ago

Particularly in teaching code.

conover• 16 years ago

I completely agree. I don't understand why foo and bar are so prevalent. Not only are you trying to describe something abstract (computer code), you are now adding another layer of human language abstraction on top of it. In many cases why not use a simple scenario people can relate to rather than foo and bar.

roundsquare2• 16 years ago

I think I once used stuff as a variable name before.

fleitz• 16 years ago

What it is about code written in languages that prefix variables with $ that results in unmaintainable code?

I'd personally vote for i and j

Mea Culpa: I've written my fair share of horrid code in PHP and Perl.

sketerpot• 16 years ago

When you use i and j as loop indices, everybody knows what you're talking about. It's idiomatic. How is that bad variable naming if its the clearest thing for everyone?

nailer5• 16 years ago

> How is that bad variable naming if its the clearest thing for everyone?

The clearest thing for me would be:

    channel.open()

Which indicates to me that a channel is being opened.

Rather than

    i.open()

Which means nothing to me unless I find and read some other line.

mseebach• 16 years ago

$data is a perfectly fine variable name, if it's used in the correct context. Such as pulling a result set out of a database. In that case, it's exactly like using i in a for loop.

Anything postfixed with 2 is more shady, I agree, but the absolute worst variable names are the ones that say they are something they're not - such as a column named "tablename_key" - which is actually a foreign key, but not in "tablename".

roundsquare2• 16 years ago

Such as pulling a result set out of a database.

Generally, I'd disagree, as does the article. If you can specify what kind of data it is, thats useful. customer_data, sample_data, etc...

The only time I'd say you might be right is if you are using it in a generic method for retrieving data, but even then I think result_data is better.

mziulu• 16 years ago

I'm guilty of using tmp quite a lot. On my defense though, it's usually just that, temporary: I end up refactoring it down the road (most of the times)!

reitzensteinm2• 16 years ago

I disagree, depending on the context. Data is an acceptable variable name to refer to binary blobs that don't have a type, eg, this is roughly the low level class that holds data that I'm streaming in (files may either be in a pack file or downloaded while the game is played):

class packFile { var name:String; var location:String; var downloadPriority:Int; var data:Array<Byte>; }

There may be a better name than data, but I can't think of one off the top of my head, and it's certainly not a bad one.

rlpb• 16 years ago

Similarly, when dealing with a small finite number of data, an integer at the end makes sense too.

For example: int add(int operand1, int operand2) { return operand1+operand2; }

cperciva• 16 years ago

I generally go with buf for a buffer containing unstructured data. It seems a bit more logical, although I'm not really sure why.

khafra• 16 years ago

It's more informative. "buf" gives you a few more bits of information about the source and purpose of the data than "data" does.

dmlorenzetti• 16 years ago

Another example: in my work group, "data" specifically means "measurements made in the real world." Numbers generated by a computer simulation don't qualify. So in our code, "data" could be a perfectly meaningful variable name.

Personally, the worst variable name I've ever seen was "C". This was a vector of concentrations. Unfortunately, the language was Fortran-77-- where a "C" in column 1 indicates a comment line.

reitzensteinm2• 16 years ago

Wow, I think you actually may have won. That's a terrible name for a variable given the context. You would probably have nightmares for years after maintaining a project like that :)

nailer5• 16 years ago

You forgot 'i'.

Yes, I know you're iterating over something.

Best case scenario: you named that something well so all I have to do in your great big for loop is scroll up, work out what you meant, and apply that to the code I care about, being mildly annoyed.

Worst case scenario: the something is also badly named and I have to open up a debugger and set a trace to work out whether the iterable is people, channels, cows, or dinosaurs.

Yes I know this is common behaviour. So are many other bad things.

panic• 16 years ago

If you can't figure out what the "i" is for, the code has other problems.

nailer5• 16 years ago

I didn't say it can't be figured out at all - please don't put works into my mouth.

Code is read much more than it's written and should be created for maximum comprehension. A simple one-line method call should be understandable without having to read any surrounding line.

donaq• 16 years ago

I use $dat, so I'm off the hook.

garply• 16 years ago

I think $data2 is worse than $data.

stretchwithme• 16 years ago

how about $thing1 and $thing2

jokull• 16 years ago

That's exactly what I thought. $data is okay if the context is very obvious but enumerating is confusing, unmaintainable.

sev• 16 years ago

Worse than the worst variable names? Good variable names where, for example, $profit = $revenue

topbanana• 16 years ago

In a code review I once got pulled up for using 'i' in a 2-line function called something like DoSomethingToThings(Thing[] things)

Aegean• 16 years ago

Data is not that bad. When you're reading a device it may have a data and status register and data becomes perfectly distinct in this context.

extension• 16 years ago

Actually, status is probably the one thing worse than data.

Runners up include value, bytes, and number.

sunkencity• 16 years ago

I think that names that are wrong are worse, like something called $xmldata which doesn't contain data in xml format, or $price_in_cents which actually contains $price_in_dollars but nobody has bothered to change it.

araneae• 16 years ago

Haha, I use data all the time. Usually when I'm doing data analysis.

erikstarck• 16 years ago

A really bad variable name should confuse the reader as much as possible. If I remember my compiler design classes correctly Pascal (?) allows you to name variables the same as language constructs. That means you can write something like

FOR FOR = WHILE WHILE WHILE = FOR

Now THAT'S bad variable names. :)

Isn't there an example like this in the Dragon Book?

aphyr• 16 years ago

Often when I read something from a file or socket, prior to parsing, it's called data. Same goes for the information to be inserted into a template, or intermediate structures when transforming datasets or documents without knowing their type.

Data is the variable name you use when you don't know, or can't specify, what you're dealing with.

crpatino2• 16 years ago

$r2d2 and $c3po

...seriously

The world's two worst variable names

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