Is anything in programming truly evil?

Question

So, there are a bunch of questions appearing asking is X evil, is Y evil.

My view is that there are no language constructs, algorithms or whatever which are evil, just ones which are badly used. Hell, if you look hard enough there are even valid uses of goto.

So does absolute evil, that is something which is utterly incompatible with best practice in all instances, exist in programming? And if so what is it? Or is it just bad programmers not knowing when something is appropriate?

Edit: To be clear, I'm not talking about things programmers do (such as not checking return codes or not using version control - they're choices made by bad programmers), I mean tools, languages, statements, whatever which are just bad...

Michael K · Answer 1 · 2012-02-10T16:56:19.750

There is no true evil in programming.

<rant>

The reason so many people think that there are evil things is that it is pounded into their heads when they first take their programming classes. "Don't use goto! Always normalize your databases! Never, ever use multiple inheritance!" These are hammered in because these "evil" practices are so easily abused, not because they are inherently bad. There are so few uses of them that you can get away with saying "never" at first. What is truly evil is saying, "There is no reason to consider anything that is not a 'best practice'", because there is always a place where that very way is perfect.

</rant>

score 58 · Answer 2 · answered Dec 21 '10 at 14:37

58

Guns dont kill people, people kill people.

In the same way, dev-tools are not evil, the things programmers do with them could be.

answered Dec 21 '10 at 14:37

guiman

2,088
13
17

score 45 · Accepted Answer · answered Dec 21 '10 at 14:53

45

Magic numbers.
Implicitness is inherently evil, and here's the reason why:

answered Dec 21 '10 at 14:53

user8865

431

score 36 · Answer 4 · answered Dec 21 '10 at 18:31

36

Is anything in programming truly evil?

Absolutely. Failure to use your brain and think about what you're doing and why you're doing it is the root of all programming evil.

answered Dec 21 '10 at 18:31

Greg D

231
2
5

score 25 · Answer 5 · answered Dec 21 '10 at 19:07

25

Empty generic exception handlers i.e. :

catch(Exception ex)
{
}

I don't doubt that someone can give me a valid use case - but, to be honest, its going to be seriously creative... and at the very least you need an explanation.

answered Dec 21 '10 at 19:07

Murph

7,843

score 19 · Answer 6 · answered Dec 21 '10 at 14:47

Perhaps I can flip the question around, and ask if there is anything in programming that is absolutely and perfectly good? If you can't think of one thing (I know I can't), then the concept of evil is also just as muddy.

There are common behaviors that lead to mistakes, misunderstandings, and other general confusion--but to say that language feature X is inherently evil is to admit that you really don't understand the purpose of feature X.

There are common behaviors that can save a lot of heartache and avoid some misunderstandings--but to say that language feature Y is inherently good is to admit that you don't fully understand all the implications of using feature Y.

We are a people of finite understanding, and strong opinions--a dangerous combination. Hyperbole is just a way of expressing our opinions, exagerating facts until they become fiction.

Nevertheless, if I can avoid behaviors that lead to problems and pursue behaviors that avoid them, I just might be a bit more productive. At the end of the day that's what it's all about.

score 13 · Answer 7 · answered Dec 22 '10 at 09:00

13

The only thing that springs to mind is this:

#DEFINE TRUE FALSE
#DEFINE FALSE TRUE

But once again, that's just plain old misuse hehe.

answered Dec 22 '10 at 09:00

Kyle Rosendo

416

user281377 · Answer 8 · 2010-12-21T18:59:13.227

Everything that happens to work just by accident is inherently evil.

Let's consider the following C program, which happens to actually work on my machine, using default compiler options:

#include <stdio.h>
int main(int argc, char *argv[]) {
   char string[10];
   int y;
   for (y=0; y<10; string[12]++) {
      printf("%d\n", y);   
   }
}

Nothing, really nothing could ever excuse the way this program increments the loop counter. It's just a undefined effect that happens to do the right thing on my machine, my compiler, my default options.

score 10 · Answer 9 · answered Dec 21 '10 at 16:39

10

I think skinning, auto-updaters that perpetually sit in the systray, applications that hijack file associations and other system settings, are straight evil.

Along with flash-only websites.

answered Dec 21 '10 at 16:39

whatsisname

27,703

score 9 · Answer 10 · answered Dec 21 '10 at 21:32

So does absolute evil, that is something which is utterly incompatible with best practice in all instances, exist in programming? And if so what is it?

Yes; the standard C library function gets(). It's evil enough that the C standards committee has officially deprecated it, and it is expected to be gone from the next version of the standard. The mayhem caused by that one library call is scarier than the prospect of breaking 30+ years' worth of legacy code -- that's how evil it is.

score 8 · Answer 11 · answered Dec 21 '10 at 19:51

8

Easy, IBM Rational ClearCase is an atrocity.

answered Dec 21 '10 at 19:51

Christoffer Hammarström

301

score 7 · Answer 12 · answered Dec 21 '10 at 14:37

So does absolute evil, that is something which is utterly incompatible with best practice in all instances, exist in programming?

Of course not. It's like asking if anything in my toolbox is evil. My hammer is a great "good" to me, unless my four year old gets her hands on it.

score 6 · Answer 13 · answered Dec 21 '10 at 14:51

6

Today's evil was yesterdays perfect. It's evolution.

answered Dec 21 '10 at 14:51

Heath Lilley

1,280

score 6 · Answer 14 · answered Dec 21 '10 at 14:59

Not to be too serious, but ...

We have very myopic views of "evil". People who kill lots of other people are evil. People who steal from others are evil. Every nation (that I know of) has some evil in their past. Some would like to deny it.

Is there evil in programming? We innocent programmers might like to think "not really". However, once I had a conversation with the inventor of a widely-used hierarchical database, on this very subject. Want to know who was one of the best customers? The secret police of Communist Poland.

Is there evil in the world now? You bet. And are they using programmers? You bet.

score 6 · Answer 15 · edited Apr 12 '17 at 07:31

Null is the root of Evil!

https://softwareengineering.stackexchange.com/questions/22912/null-references-the-billion-dollar-mistake-closed

The Billion Dollar Mistake: I call it my billion-dollar mistake. It was the invention of the null reference in 1965. At that time, I was designing the first comprehensive type system for references in an object oriented language (ALGOL W). My goal was to ensure that all use of references should be absolutely safe, with checking performed automatically by the compiler. But I couldn't resist the temptation to put in a null reference, simply because it was so easy to implement. This has led to innumerable errors, vulnerabilities, and system crashes, which have probably caused a billion dollars of pain and damage in the last forty years. In recent years, a number of program analysers like PREfix and PREfast in Microsoft have been used to check references, and give warnings if there is a risk they may be non-null. More recent programming languages like Spec# have introduced declarations for non-null references. This is the solution, which I rejected in 1965. C.A.R. Hoare, 2009

score 5 · Answer 16 · answered Dec 21 '10 at 23:30

5

Copy-paste code.

If you don't itch when you are doing that, you are not a real programmer.

answered Dec 21 '10 at 23:30

egarcia

291

score 5 · Answer 17 · answered Dec 22 '10 at 15:59

I personally find Donald Knuth's phrase: "premature optimization is the root of all evil" as the first evil thing in programming. In an expirienced point of view (that says that i have failed for this).

Actually, the phrase says something like: Don't try to understand the problem in a particular enviroment, particular PC or set of users before you get in deep into the problem.

score 4 · Answer 18 · answered Dec 21 '10 at 22:44

I'm surprised no one has floated Globals as a true evil. No better way to be programming in an environment about which you have no idea of the parameters and virtually no control over what happens to them. Chaos! I have a strict ban on the use of global variables in all of my coding.

score 3 · Answer 19 · answered Dec 21 '10 at 14:43

3

No tool is inherently evil. Its existence may be utterly foolish for all but a single use case but that does not make it evil. It puts the onus of deciding the proper use on the programmer.

answered Dec 21 '10 at 14:43

Bob Roberts

1,847

score 3 · Answer 20 · answered Dec 21 '10 at 19:10

3

Well, I thought Microsoft is/was considered evil and now recently Oracle is the most evil thing in the world.

answered Dec 21 '10 at 19:10

Uwe Keim

347
4
13

score 3 · Answer 21 · answered Dec 21 '10 at 21:48

3

I know i said i wouldnt make a post but i'll write one answer. As much as everyone else says no there are no evils i'll say yes there are some absolute evils

Setjmp/LongJmp is pure evil.

answered Dec 21 '10 at 21:48

score 3 · Answer 22 · edited Jul 17 '12 at 08:51

3

What does the FAQ mean by "such and such is evil"?

It means such and such is something you should avoid most of the time, but not something you should avoid all the time. For example, you will end up using these "evil" things whenever they are "the least evil of the evil alternatives." It's a joke, okay? Don't take it too seriously.

edited Jul 17 '12 at 08:51

mmdemirbas

507

answered Dec 22 '10 at 01:03

Merlyn Morgan-Graham

911

score 3 · Answer 23 · answered Dec 22 '10 at 02:04

3

Redundant code is very very evil.

answered Dec 22 '10 at 02:04

Vanchinathan Chandrasekaran

101

score 2 · Answer 24 · edited Aug 02 '11 at 04:31

2

Code in your native language (not English), write documentation in your native language. And then outsource the project to an Indian company.

That's evil for you!

P.S.: For the record, it happened, and the Indians didn't find it very funny.

edited Aug 02 '11 at 04:31

answered Dec 21 '10 at 18:14

Demian Kasier

784
3
13

Robert · Answer 25 · 2010-12-22T01:36:44.267

Though any tool can be used for good and evil, some tools are evil because they often surprise programmers who don't use them frequently.

I consider the unsigned right shift operator (>>>) in Java evil (surprisingly improper) when working with integers that are shorter than 32 bit.

Say you have a byte b with value -1.

byte b = -1;  // binary: 1111 1111

The unsigned right shift operator shifts zeroes into the leftmost bits. So one assumes a shift by 7 to result in 1.

b >>>= 7;  // binary: 0000 0001 ?

But instead this operation does nothing at all. b is still -1.

Even all of the following 25 shifts do nothing:

byte b = -1;
for (int i = 0; i < 25; ++i) {
    b >>>= i;
    System.out.println(b); // always outputs -1
}

This happens because b>>>=7 roughly translates to

                                  1111 1111

1) the byte gets widened to a 32 bit int to make shifting possible
    1111 1111 1111 1111 1111 1111 1111 1111

2) the shift happens
    0000 0001 1111 1111 1111 1111 1111 1111

3) the resulting int gets narrowed to a byte again
                                  1111 1111

You would have to replace

b >>>= i;

by

b = (b & 0xFF) >>> (i % 8);     // >> would also work this time

to make it work as 'expected'.

Kenji Kina · Answer 26 · 2010-12-22T19:06:09.823

I'm gonna turn this around and say that while there's no absolute evil, there are tools and constructs which make it more plausible for our feeble humans with such a limited skull size to make mistakes than others.

So I'd say you could talk about the evilness of a construct based on how likely people are to make mistakes with it. Sure you can cut bread with a knife or with a chainsaw with blades as grip, but one is more likely to cause damage than the other, even though you may be able to pull it off with enough care.

score 1 · Answer 27 · answered Dec 21 '10 at 14:34

1

I'm tempted to say continuations, but I think the correct answer is that there is no objective, absolute evil in programming. On the other hand, even the best tools can be abused.

answered Dec 21 '10 at 14:34

Larry Coleman

6,111

score 1 · Answer 28 · answered Dec 21 '10 at 18:40

Programming, per se, I think, is not inherently evil. However, programming is very often a social activity, and disrespecting those around you can be very evil. People often forget that most code is going to be shared with others; mostly read, sometimes written too. Be it open source, a product that a company is releasing, or a small piece of patching up a consultant is hired for, programs are going to be read.

That's half the reason why so many "considered harmful" articles exist, or why people say "never". Making life difficult for others is the very root of all evil. Isn't it?

score 1 · Answer 29 · answered Dec 21 '10 at 23:21

1

Yes, there is plenty of evil to be had. For example:

Type1 variable1 = function12()
variable5 = variable1.myMethod(variable1+aGlobal);
variable2.otherMethod(anotherGlobal);

answered Dec 21 '10 at 23:21

Mud

476

score 1 · Answer 30 · answered Dec 22 '10 at 08:33

Increasing the total cost of the system for insufficient benefit. It could be too much copying and pasting, too complex an architecture, or using pricey but ineffective commercial products. Generally speaking all software techniques are aimed at reducing the total cost of a system, and if we end up with a overly expensive system then we have done wrong.

score 1 · Answer 31 · answered Dec 22 '10 at 14:33

I think there are evil things in programming, but I don't use the term pejoratively.

Evil is when code pretends to behave in one way, but in reality behaves in a very different fashion, and in a way that hurts a unenlightened rational programmer. I often refer to this as a type of "Magic." Magic is anything who's functionality is "hidden" from the programmer, and it comes in different styles.

Example: in Scheme the functions "car" and "cdr" could be implemented using functions only, however, they are not. Instead they are implemented at a lower level imperatively because that runs faster on most computers. I'd call this "white magic." Its not evil, but its definitely magic.

By comparison the unique number NAN in Javascript is not equal to any other number... even itself. This is "black magic." I don't want to get into a discussion of why you have NAN in Javascript (or why you have both Infinity and NaN), but you can see why a such a simple concept would be useful to a language with only floating point numbers. However, having a constant number which cannot be tested for in the same way as other constant numbers is not something one would expect. Fortunately Javascript provides isNAN to help solve this issue, but if you are unaware of NaN's unique property you might write the following code and get burned:

if(x == NaN)

or if you're clever you might try the following with the same results

if(x === NaN)

I joking refer to this as getting "mana burned" (it is magic afterall...).

I realize there are good reasons why you want things which are not numbers to be automatically equal to themselves, but you have to remember that for IEEE floating point numbers NaN has a specific bit sequence and it is similar to other numbers in this respect. If you treat Javascript NaN the way you might treat an IEEE floating point NaN you are liable to get burned. This is both deceptive and frustrating, the former being the reason I refer to this as Evil.

Then again, its possible people think otherwise...

Manoj R · Answer 32 · 2010-12-23T10:38:55.147

1

When the deadline is near, and requirements change, design changes, and you spend 16 hours in office, that is evil.

edited Dec 23 '10 at 10:38

answered Dec 23 '10 at 06:09

Manoj R

4,056

score 0 · Answer 33 · answered Dec 21 '10 at 14:59

Is anything in programming truly evil? I mean tools, languages, statements, whatever

Nothing on that list is evil. Here is why.

Humans were created as beings with a free will. They may use their powers to go into the dark side or embrace the light side. This choice defines what comes out of their hands.

Now, those tools and frameworks were created by benevolent people who were genuinely trying to make things somehow better with a good will. Consequently, their creations (either successful or not is irrelevant) do not bear the imprint of evil. At the least they are neutral, but not malicious.

Then those tools come into the hands of other individuals. And whatever they do with them depends on those people. Even a debugger could be turned into an evil instrument in the hands of a hacker trying to remove the serial number check in some software.

But it does not redefine in any way the characteristic of the tool. They are all good. Some are more useful, some less. Some dangerous, some less. But still, they are all good and quite useful in certain scenarios.

And if a programmer by a mistake misuses a tool and causes damage, the tool does not become evil. It's just a programmer mistake, lack of knowledge, ignorance, whatever. But without any evil intent.

Bottom line is, all tools are good. We must love them all.

score 0 · Answer 34 · answered Dec 21 '10 at 15:03

There's no objective absolute evil.

The problem with things like GOTO is that it's awfully hard to USE it in a way that's not nasty. Enough so that it's hard for me sitting right here now to think of an example of GOTO that isn't code smell. But I'm willing to accept that there might be such uses, and that the problem isn't the tool itself but rather the likelihood of its abuse.

score 0 · Answer 35 · answered Dec 21 '10 at 16:51

Some programming instructions / style / conventions are very often misused to make terrible, evil if you will code, but in the hands of a master programmer they can be used in a very elegant fashion, good if you will.

On the other hand I know of nothing that can prevent incompetent or inexperienced programmers from from producing bad, evil if you will code even with the best tools, languages, and so on.

By avoiding often misused elements, such as goto, the hope is that mediocre programmers can avoid the evil and perhaps make it somewhat easier to write good code.

score 0 · Answer 36 · answered Dec 21 '10 at 18:44

Nothing is really evil not even weapons, yet we sometimes consider them as such. However with weapons we usually have a certain level of respect, we are very much aware of their danger and use them with caution; however there are still people too stupid to use them.

The same applies to any tool, the more difficult the consequences of abusing those tools are, the more likely people are abusing them.

In programming everything is more or less virtual, a program is a representation of our thought process and the long term consequences of not understanding something entirely or getting it slightly wrong are a lot harder to determine, then the immediate danger of death we are faced with when handling a gun.

This makes the tools we use and have at our disposal a lot harder to use but it also gives us an easy way to measure the skill of a programmer. The knowledge of when and how to use the tools you have is crucial to become a good programmer. You can always play it safe by restricting the set of tools but just to the guy to whom everything looks like a nail, eventually you will encounter something that no amount of hitting will fix.

score 0 · Answer 37 · answered Dec 21 '10 at 19:25

The only thing 'evil' is thinking that certain programming things are 'evil'. Various approaches - use this technique, dont use that statement, use this methodology, dont use that language, use this 'best practice', etc - are opinions.

Unfortunately, too many developers mistake opinions for objective truth.

I cringe every time I see a question on here such as 'why is [x] considered evil?'.

score 0 · Answer 38 · answered Dec 21 '10 at 21:32

Everything has it's own valid use, or it wouldn't be implemented. Things are called evil because people do not use it in a safe or proper manner. Consider this...

Is a sword evil? Nope. Just because someone may try to use a sword in a hospital does not mean it is evil. Is a can opener evil? Nope.

Everything has it's proper use. Hence, no evil.

score 0 · Answer 39 · edited May 23 '17 at 12:40

0

Visible side-effects in unexpected places.
In .Net, examples would be ToString(), Equals() / GetHashCode(), property getters, and implicit conversions.
(To be clear, I'm talking about something more than lazy instantiation or logging code)

throw new Exception(ex.Message);

Explanation

edited May 23 '17 at 12:40

Community

1

answered Dec 22 '10 at 17:35

SLaks

1,204
11
16

score 0 · Answer 40 · edited Jun 16 '20 at 10:01

I agree with the c++ FAQ on this:

[6.16] Will I sometimes use any so-called "evil" constructs?

Of course you will!

One size does not fit all. Stop. Right now, take out a fine-point marker and write on the inside of your glasses: Software Development Is Decision Making. "Think" is not a four-letter word. There are very few "never..." and "always..." rules in software — rules that you can apply without thinking — rules that always work in all situations in all markets — one-size-fits-all rules.

In plain English, you will have to make decisions, and the quality of your decisions will affect the business value of your software. Software development is not mostly about slavishly following rules; it is a matter of thinking and making tradeoffs and choosing. And sometimes you will have to choose between a bunch of bad options. When that happens, the best you can hope for is to choose the least bad of the alternatives, the lesser of the "evils."

You will occasionally use approaches and techniques labeled as "evil." If that makes you uncomfortable, mentally change the word "evil" to "frequently undesirable" (but don't quit your day job to become an author: milquetoast terms like that put people to sleep :-)

Is anything in programming truly evil?

40 Answers40