Examples of programmers being stupid

Question

List examples of programmers doing stupid things in their code.

I just came across this little baby in PHP:

if(strpos($row['themename'],"some string") !== false){

This is wrong on so many levels. First, there is the double negation in saying 'not equals false'. Then there's the explicit checking of truth (why not do ($something == false) == true while you're at it?) and finally there's the calling of strpos for a simple string comparison.

I thought it would be fun to see what other examples people can come up with.

Answer 1

#define TRUE (1)
#define FALSE (!TRUE)

The author of this C++ gem managed to define TRUE and FALSE as (a) different types, with (b) different sizes.

Genius!

Answer 2

Probably anything people have written and put live at 5pm on a Friday!

Answer 3

How about http://thedailywtf.com/?

Enough stupidity to procrastinate over for a decade in there.

Answer 4

I had to explain this one to so many students I lost count.

if(condition == true) {
    return true;
}
else {
    return false;
}

Answer 5

Uhm, it doesn't do 'not equals false' what it actually does is checks the expression and makes sure the result is not of type boolean false, not converted to boolean false as it would be if $row['themename'] was located at the start of "some string"

EDIT: Better explained here and here

Edit 2: In lieu of Graemes comment, to answer this question, I would like to claim this question as an example of a programmer doing something silly =]

Answer 6

try
{
    // do something
}
catch (Exception ex)
{
    if (ex is FileNotFoundException)
    {
        // blah
    }
    else if( ex is InvalidOperationException)
    {
        // blah
    }
    else if( ex is AnotherException)
    {
        // blah
    }
    // etc.
}

Answer 7

I've seen this used:

someVariable = GetObjectByName(ThatObject.Name)

in this sort of structure:

for i = 1 to 6
   select case i
   case 1: 
     dostuffwith(obj1)
   ..
   case 6: 
     dostuffwith(obj7)
   end select
next

And let's not forget the classic:

someFlag = True;
if(someFlag == False) 
{ 
   someFlag = True;
}

I, of course, saw the obvious problems in the above and refactored it:

for(someFlag = True; someFlag == False; someFlag = True);

After all, the original code fragment would be wrong if the assignment operation were to fail twice. My patented method allows for infinite failure.

Answer 8

Somebody wrote a loop to find out the size of an array:

int size = 0;
for (int i=0; i<array.length; i++) {
    size++;
}

That's stupid on so many levels its unbelievable.

Answer 9

return i == 7 ? true : false;

Answer 10

double val;
...
if(val == 0.1) {
  //do something
}else{
 //do something
}

assuming real number and floating number is the same thing subconsciously.

Answer 11

try
{
    // something
}
catch (Exception ex)
{
    throw ex;
}

Brilliant... you've added 7 lines of code that do nothing except corrupt the stack trace of the exception.

Answer 12

I found one time this:

if (someBoolean != false) {
    // do something
}

And another time, from same author:

if (true != false) {
    // do something
}

Answer 13

IF NOT EXISTS
    SELECT 1 FROM customer WHERE customer_id = @customer_id
BEGIN
    INSERT INTO customer
    (stuff, fluff, foo, bar, top, secret, column, names, but, still, funny)
    SELECT stuff, fluff, foo, bar, top, secret, column, names, but, still, funny
    FROM customer
    WHERE customer_id = @customer_id
END

Answer 14

/* Copyright (C) 2005 Free Software Foundation, Inc. This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.

The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */

ifndef _FEATURES_H

error "Never use directly; include instead."

endif

ifndef _PREDEFS_H

define _PREDEFS_H

/* We do support the IEC 559 math functionality, real and complex. */

define STDC_IEC_559 1

define STDC_IEC_559_COMPLEX 1

endif /* predefs.h */

um, why would you need to put that in it's own file?