Survey Results - Do you do defensive programming?

PedroMC14-May-12 1:49

14-May-12 1:49

No, it is not.

know bad as in "I always try to work out everything the user could possibly do wrong"
know good != not know bad

PMC

Re: When given the time

chriselst14-May-12 1:54

chriselst

14-May-12 1:54

I think I may have explained myself poorly originally.

By everything the user could do I meant all the points in the UI where they enter something rather than all the possible data they could possibly enter.

Basically what I was trying to say was don't assume you know everything a user will try to do.

Every man can tell how many goats or sheep he possesses, but not how many friends.

Re: When given the time

Fabio Franco14-May-12 10:15

Fabio Franco

14-May-12 10:15

I'll have to agree with Pedro.

Say the user ID should not accept spaces or special characters, so you code something to block all spaces and special characters of standard languages.

That will work until you get a Chinese user. Your database is not prepared to accept unicode data and there you go, your application just broke.

Now, if you coded in the first place to accept only [a-z], [A-Z] and [0-9] characters, the chances to fail that validation would disappear.

So yes, there is a difference between allowing the valid and disallowing the invalid. It has a different perspective. Even worse, imagine having to take into account all alphabets from all cultures.

To alcohol! The cause of, and solution to, all of life's problems - Homer Simpson
----
Our heads are round so our thoughts can change direction - Francis Picabia

We have many defensive programmers.

mojp13-May-12 23:16

mojp

13-May-12 23:16

They say things like:

"It worked on my machine"

"That's not how you described it"

"That wasn't specified"

"Its not my fault, blame the [insert guilty party]" , e.g. "Spec", "Testers", "Users" .

Re: We have many defensive programmers.

jim lahey13-May-12 23:50

jim lahey

13-May-12 23:50

beat me to it Smile | :)

Yes, I do

Prasad_Kulkarni13-May-12 22:42

Prasad_Kulkarni

13-May-12 22:42

I use defensive programming;
-by proper unit testing while developing a particular module.
-by proper comment lines (for behavior of respective function/ method) and regions.
and of course, meaningful naming conventions (by which one should easily come to know what's its use) all over in application.

Re: Yes, I do

AlexCode14-May-12 21:26

AlexCode

14-May-12 21:26

Apart of Unit Testing, everything on your list is mere maintenance best practices.
Comments and naming conventions won't do any good to your software upon an unexpected input or if it needs to scale.

one of the principals of testing

R. Erasmus13-May-12 22:36

R. Erasmus

13-May-12 22:36

One of the principals of testing is to ensure whether a function is robust.
A function is made robust through means of defensive programming.

To the people that doesn't understand what defensive programming is:
An simple example:

C++

bool increment_by_one(unsigned int32* input1)
{
  bool status = FALSE;

  /* defensive programming - Ensure's that 'NULL pointer exception' or 'memory violation'
     doesn't occur */
  if (input1 != NULL)
  {
    *input++;
    status = TRUE;
  }
  else
  {
    status = FALSE;
  }

  return status;
}

"Program testing can be used to show the presence of bugs, but never to show their absence."

<< please vote!! >>

modified 14-May-12 5:02am.

WTF defensive programming

Ra-one13-May-12 21:31

Ra-one

13-May-12 21:31

I don't know about it, In the environment I work is to progressive and need fast and prompt development that, We can think of defense.

Read the subject line again.... Its an attack on the defensive programming (what ever it is). Mad | :mad:

Re: WTF defensive programming

OriginalGriff13-May-12 21:52

OriginalGriff

13-May-12 21:52

Why would you want to attack something when you don't have an idea what it is?

Ideological Purity is no substitute for being able to stick your thumb down a pipe to stop the water

Re: WTF defensive programming

chriselst13-May-12 23:48

chriselst

13-May-12 23:48

Because that is the natural human reaction.

"What is it?"
"I don't know"
"Let's kill it"

Every man can tell how many goats or sheep he possesses, but not how many friends.

Re: WTF defensive programming

JOAT-MON14-May-12 7:08

JOAT-MON

14-May-12 7:08

I thought the natural human reaction was to "poke-it-with-a-stick":

ChrisElston wrote:
"What is it?"

"I don't know"

~~"Let's kill it"~~ "Let's poke it with a stick."

Jack of all trades ~ Master of none.

Re: WTF defensive programming

JackDingler14-May-12 7:20

JackDingler

14-May-12 7:20

Or hit it with a rock.

Re: WTF defensive programming

Fabio Franco14-May-12 10:19

Fabio Franco

14-May-12 10:19

JOAT-MON wrote:
I thought the natural human reaction was to "poke-it-with-a-stick"

Isn't it to say that God made it this way?

To alcohol! The cause of, and solution to, all of life's problems - Homer Simpson
----
Our heads are round so our thoughts can change direction - Francis Picabia

Re: WTF defensive programming

Ra-one14-May-12 21:30

Ra-one

14-May-12 21:30

..and yes of course I am an human Smile | :)

Re: WTF defensive programming

JackDingler14-May-12 7:19

JackDingler

14-May-12 7:19

I had a boss at one time like that. His code constantly crashed in production. It took the team over month with overtime, to fix one of his projects that he developed, using his leet and fast programming skills.

First

ycg16691113-May-12 21:26

ycg166911

13-May-12 21:26

I'm a students

Re: First

OriginalGriff13-May-12 21:52

OriginalGriff

13-May-12 21:52

Which means you're permanently drunk and can't read the subject? Big Grin | :-D

Ideological Purity is no substitute for being able to stick your thumb down a pipe to stop the water

Re: First

Old Nic13-May-12 23:36

Old Nic

13-May-12 23:36

Are you a students of english?

Re: First

ycg16691114-May-12 0:22

ycg166911

14-May-12 0:22

Yes,but i english is bad,Please forgive me.

Well

Prasad_Kulkarni13-May-12 20:31

Prasad_Kulkarni

13-May-12 20:31

I really don't have any idea about what exactly defensive programming is Confused | :confused:

Re: Well

codeBegin13-May-12 20:32

codeBegin

13-May-12 20:32

me too..

Re: Well

OriginalGriff13-May-12 21:53

OriginalGriff

13-May-12 21:53

Wiki[^]

Ideological Purity is no substitute for being able to stick your thumb down a pipe to stop the water

Re: Well

Prasad_Kulkarni13-May-12 22:33

Prasad_Kulkarni

13-May-12 22:33

Thank you

Re: Well

codeBegin13-May-12 23:02

codeBegin

13-May-12 23:02

Thank you OriginalGriff Smile | :)

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Option	Votes	%
Yes, I use defensive programming always	193	16.67
I use defensive programming mostly	510	44.04
I use defensive programming rarely	198	17.10
No, I don't use defensive programming design	59	5.09
I have no idea of what you speak.	198	17.10
Total	1,158	100%