Long-held, incorrect programming assumptions [closed] - methodology

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I am doing some research into common errors and poor assumptions made by junior (and perhaps senior) software engineers.
What was your longest-held assumption that was eventually corrected?
For example, I misunderstood that the size of an integer is not a standard and instead depends on the language and target. A bit embarrassing to state, but there it is.
Be frank; what firm belief did you have, and roughly how long did you maintain the assumption? It can be about an algorithm, a language, a programming concept, testing, or anything else about programming, programming languages, or computer science.

For a long time I assumed that everyone else had this super-mastery of all programming concepts (design patterns, the latest new language, computational complexity, lambda expressions, you name it).
Reading blogs, Stack Overflow and programming books always seemed to make me feel that I was behind the curve on the things that all programmers must just know intuitively.
I've realized over time that I'm effectively comparing my knowledge to the collective knowledge of many people, not a single individual and that is a pretty high bar for anyone. Most programmers in the real world have a cache of knowledge that is required to do their jobs and have more than a few areas that they are either weak or completely ignorant of.

That people knew what they wanted.
For the longest time I thought I would talk with people, they would describe a problem or workflow and I would put it into code and automate it. Turns out every time that happens, what they thought they wanted wasn't actually what they wanted.
Edit: I agree with most of the comments. This is not a technical answer and may not be what the questioner was looking for. It doesn't apply only to programming. I'm sure it's not my longest-held assumption either, but it was the most striking thing I've learned in the 10 short years I've been doing this. I'm sure it was pure naivete on my part but the way my brain is/was wired and the teaching and experiences I had prior to entering the business world led me to believe that I would be doing what I answered; that I would be able to use code and computers to fix people's problems.
I guess this answer is similar to Robin's about non-programmers understanding/caring about what I'm talking about. It's about learning the business as an agile, iterative, interactive process. It's about learning the difference between being a programming-code-monkey and being a software developer. It's about realizing that there is a differnce between the two and that to be really good in the field, it's not just syntax and typing speed.
Edit: This answer is now community-wiki to appease people upset at this answer giving me rep.

That I know where the performance problem is without profiling

That I should have only one exit point from a function/method.

That nonprogrammers understand what I'm talking about.

That bugfree software was possible.

That private member variables were private to the instance and not the class.

I thought that static typing was sitting very still at your keyboard.

That you can fully understand a problem before you start developing.

Smart People are Always Smarter than Me.
I can really beat myself up when I make mistakes and often get told off for self-deprecating. I used to look up in awe at a lot of developers and often assumed that since they knew more than me on X, they knew more than me.
As I have continued to gain experience and meet more people, I have started to realise that oftentimes, while they know more than me in a particular subject, they are not necessarily smarter than me/you.
Moral of the story: Never underestimate what you can bring to the table.

For the longest time I thought that Bad Programming was something that happened on the fringe.. that Doing Things Correctly was the norm. I'm not so naive these days.

I thought I should move towards abstracting as much as possible. I got hit in the head major with this, because of too much intertwined little bits of functionality.
Now I try keep things as simple and decoupled as possible. Refactoring to make something abstract is much easier than predicting how I need to abstract something.
Thus I moved from developing the framework that rules them all, to snippets of functionality that get the job done. Never looked back, except when I think about the time I naively thought I would be the one developing the next big thing.

That women find computer programmers sexy...

That the quality of software will lead to greater sales. Sometimes it does but not always.

That all languages are (mostly) created equal.
For a good long while I figured that the language of choice didn't really make much of a difference in the difficulty of the development process and the potential for project success. This is definitely not true.
Choosing the right language for the job is as important/critical as any other single project decision that is made.

That a large comment/code ratio is a good thing.
It took me a while to realize that code should be self documenting. Sure, a comment here and there is helpful if the code can't be made clearer or if there's an important reason why something is being done. But, in general, it's better to spend that comment time renaming variables. It's cleaner, clearer and the comments don't get "out of sync" with the code.

That programming is impossible.
Not kidding, I always thought that programming was some impossible thing to learn, and I always stayed away from it. And when I got near code, I could never understand it.
Then one day I just sat down and read some basic beginner tutorials, and worked my way from there. And today I work as a programmer and I love every minute of it.
To add, I don't think programming is easy, it's a challenge and I love learning more and there is nothing more fun than to solve some programming problem.

"On Error Resume Next" was some kind of error handling

That programming software requires a strong foundation in higher math.
For years before I started coding I was always told that to be a good programmer you had to be good at advanced algebra, geometry, calculus, trig, etc.
Ten years later and I have only once had to do anything that an eighth grader couldn't.

That optimizing == rewriting in assembly language.
When I first really understood assembly (coming from BASIC) it seemed that the only way to make code run faster was to rewrite it in assembly. Took quite a few years to realize that compilers can be very good at optimization and especially with CPUs with branch prediction etc they can probably do a better job than a human can do in a reasonable amount of time. Also that spending time on optimizing the algorithm is likely to give you a better win than spending time converting from a high to a low level language. Also that premature optimization is the root of all evil...

That the company executives care about the quality of the code.
That fewer lines is better.

I would say that storing the year element of a date as 2 digits was an assumption that afflicted an entire generation of developers. The money that was blown on Y2K was pretty horrific.

That anything other than insertion/bubble sort was quite simply dark magic.

That XML would be a truly interoperable and human readable data format.

That C++ was somehow intrinsically better than all other languages.
This I received from a friend a couple of years ahead of me in college. I kept it with me for an embarrassingly long time (I'm blushing right now). It was only after working with it for 2 years or so before I could see the cracks for what they were.
No one - and nothing - is perfect, there is always room for improvement.

I believed that creating programs would be exactly like what was taught in class...you sit down with a group of people, go over a problem, come up with a solution, etc. etc. Instead, the real world is "Here is my problem, I need it solved, go" and ten minutes later you get another, leaving you no real time to plan out your solution efficiently.

I thought mainstream design patterns were awesome, when they were introduced in a CS class. I had programmed about 8 years as hobby before that, and I really didn't have solid understanding of how to create good abstractions.
Design patterns felt like magic; you could do really neat stuff. Later I discovered functional programming (via Mozart/Oz, OCaml, later Scala, Haskell, and Clojure), and then I understood that many of the patterns were just boilerplate, or additional complexity, because the language wasn't expressive enough.
Of course there are almost always some kind of patterns, but they are in a higher level in expressive languages. Now I've been doing some professional coding in Java, and I really feel the pain when I have to use a convention such as visitor or command pattern, instead of pattern matching and higher order functions.

For the first few years I was programming I didn't catch on that 1 Kbyte is technically 1024 bytes, not 1000. I was always a little perplexed by the fact that the sizes of my data files seemed slightly off from what I expected them to be.

That condition checks like:
if (condition1 && condition2 && condition3)
are performed in an unspecified order...

That my programming would be faster and better if I performed it alone.

Related

What are the essential concepts all programmers should learn and use? [closed]

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Closed 10 years ago.
I'm currently learning to program, and I didn't take CS classes so I'm basically starting out on the bottom. I have been putting together code on and off for many years, but haven't really had a good understanding of essential concepts needed for enganging in bigger projects. Object-orientation is an obvious one, and I feel I'm beginning to understand some of the concepts there. Then there is a lot of buzz and methodology, such as MVC, UML, SCRUM, SOLID and so foth and so on.. I've looked at many of these but I'm always stumped as most explanations seem to require some understanding of other concepts.
I want to learn this stuff the "right" way, so where do I begin?
What are the overarching constructs I need to understand that enable me to understand all the underpinnings of software architecture/design/development?
What am I missing?
Are there constructs and concepts that can and should wait until I've cleared the foundation?
The SOLID principles are probably the most important.
From those you understand the motivation behind using a pattern such as MVC, why people think of persistence ignorance as important and so on. They are at the core of the majority of good practices.
Loose coupling, high cohesion.
And as for books, Code Complete covers almost everything at some level, at least.
Software development is a HUGE arena and you should be careful that you don't take on too much too quickly. Unless you're going to go in the direction of functional programming I'd suggest you start off by making sure you fully understand the concepts surrounding OO design and programming as this should be your foundation.
Once you understand that well you'll be able to understand design patterns a lot better and get a feeling for when to use them.
I'd suggest you try out a few languages till you find one you feel comfortable with, personally my favourite language is Ada which is a very pure OO language but in the business world I work in C# which still has a lot of issues but these are outweighed by the more vibrant job market.
I wouldn't worry too much about Scrum at this stage as you need to focus more on your dev skills before worrying about project management.
The most important thing is to work with as much code as possible, download lots of good reference solutions and work through the code till you understand it, and try and keep an eye on the development trends.
If its viable you may also want to considering attending some developer conferences too as these can be very inspirational.
Stay away from ACRONYMS (including those you've listed) and Methodologies(tm). At least in the beginning.
Read good books. Start with this one: Pragmatic Programmer. Learn algorithms and data structures, possibly from Introduction to algorithms by Cormen et al.
Write a lot of code. Practice is more important than anything else.
How to test software with unit tests. Being able to do that will solve 90% of all the other issue automatically since you can't test while they are around.
When you know how to test, you can start on advanced topics like design.
I'd recommend "Object Oriented Analysis and Design with Applications" by Grady Booch et al. The latest editoin has detailed explanation of concepts of OOAD including MVC, UML (which he invented), and discussions on how to manage the whole process of software development. The second part of the book exemplifies all this by developing 5 sample systems (with sometimes orthogonal aspects from the very core).
Another good one is of course Design Patterns by GoF which will give you an idea of loose coupling, ways to efficient encapsulation and reuse of code, etc
For what concerns the algorithmic part, take any book which is not bounded to a particular programming language. My favorite is Introduction to Algorithms by T. H. Cormen et al, it gets a bit theoretical at some points, but I especially like it when they are proving certain things and not just asking you to believe it.
When you are working with any modern general purpose language, it is probably a good idea to get a handle on patterns (MVC or Model-View-Controller is one). The book by the "gang of four" is a must read for this, or at least research a few and use it as a reference.
clicky
Refactoring is another concept that should be in your arsenal. The book by Martin Fowler on this subject is a very nice read and helps understand the aforementioned patterns better also a little explanation about UML is included.
Can't post more than one hyperlink so...
search on amazon for: Refactoring, Improving the design of existing code
When you want to communicate your designs UML (Unified Modelling Language) is the 'tool' of choice for many people. However UML is large and unwieldy but Martin Fowler (again) has managed to boil it down to the essentials.
search on amazon for: UML Distilled (make sure you get the most recent one)
SCRUM is one of many methods that is used to manage software development groups, I do not think there is much merit in learning that when you are just starting out or on your own. Especially not in detail.
Hope it helps...
PS: SOLID I haven't heard about yet, somebody else has to help you there.
You'd have a decent foundation if you surveyed basic Data Structures, Algorithms, and Algorithms Analysis.
I think that you should start coding real world problems to get a feel for problems in the programming domain.
Then you have a better background to understand why objects are important. Then, after managing objects, you will learn why patterns and OO principles are important.
Personally, I highly recommend the Agile Software Development, by Robert C Martin.
But it may be a long and tiresome read unless you have a feel for the problems being solved. I'm afraid that you may need 500-1000 hours of coding at the minimum before you get an appreciation that the problems being solved are real.
And it probably takes 7000+ hours before you develop an instinctive heart-felt pain from merely reading the problems, making this sort of book become the page-turner that it should be.
Regrettably, many of the sound practices that you should develop are only appreciated after having to live with your code over time. If you just do many excercises and abandon the code afterwards just "because it works", then you are missing out on the greatest pain of all. It is a luxury our industry does not have, and "technical debt" is a very very real and costly to those with large code bases.
I feel kinda silly answering my own question like this.. :) But one valuable resource I've found for learning to write code, is the Euler Project at http://www.projecteuler.net
It's basically a collection of mathmatical problems that you solve by writing your own solution to it. Once you've found the answer to a particular problem, you're allowed access to that problem's forum where different solutions are discussed. I was amazed at how much I was learning in a) solving a challenge, b) reading about other peoples approaches and c) how many programming languages there are out there! :)
The problems start out easy (you can tell by the number of people who's solved them) and progress to harder and harder problems.
Currently I'm working on problem #3, having solved the previous two... I recommend you start chippin' away at them, no matter your level!

Does it make sense to study COBOL? [closed]

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Closed 11 years ago.
I have had a talk with a friend of mine about the relative vulnerability of different types of IT workers to unexpected unemployment (e.g. layoffs, company going out of business, obsolete skills etc.)
as it seems COBOL developers (or maintainers?) seems very secure in their positions, regardless of the state if the economy or even how good they are. With so much critical COBOL code being around on the one side and the deminishing number of COBOL know-hows on the other , it actually makes sense to recommend someone starting their way in the IT world and looking for a relativity secure job to study and intern in COBOL!
what do you think ?
I started as a programmer with Cobol more than 10 years and worked with Cobol at different institutions then for several years.
Cobol as a technology is fairly easy to learn if you know any imperative programming language.
Cobol itself differs a lot on various platforms and versions - thus it is difficult to study the right version before hand.
The real challenge with Cobol is not the technology, but the complexity of the underlying business and the lack of documentation of the systems/programs. Thus the real value of a lot of COBOL experts is in fact not the actual COBOL knowledge, but the understanding of the business.
I think it makes sense to be a good software developer. For me personally, your question sounds a bit like: "What silo should I occupy to feel secure about my job and stop improving myself?" I know you didn't mean exactly this. But anyway, that's not the best motivation for choosing a career path.
I'd say: try tinkering on some COBOL code. If it's fun for you, go for it! Just as for dozens of other things you should try.
You have to understand that the arguments you made, are relative to time, that is now. We have seen time and again, how technologies seems so prominent at time t and becomes obsolete at time (t + 0.001). Though your arguments rotate around the very fact that COBOL is more or less obsolete, but they may find a new way to deal with it and again you become out of job. So here's rule number 1:
Never rely on one single technology.
With time, they always find ways to have lesser and lesser resources do the same thing. All you can do is to be a smart software professional. When you get the core part of computer programming, technologies wont matter, with time you could just learn them. So here's the second rule:
Don't just try to expertise a
technology, expertise software
engineering
Finally, to survive in IT you always need to be cutting-edge-aware. Also immaterial of all the above, you can still be laid off depending on the harshness of the recession. So finally:
Keep a back up line of work ready,
tommorow IT industry might not be
there :)
Try it, and if you like it then study it seriously.
If you learn it too well you may find you end up stuck in a COBOL role with no way out; it begins slowly and then you are drawn in because the knowledge is very specialised. If you enjoy it, that's fine - but if you try it and don't like it, then don't continue.
IMHO, It always makes sense to study a new language.
It's true that there's a lot of COBOL code running today, and much of that code is mission critical. However, how much actual COBOL coding is happening? I see large enterprises gradually replacing those COBOL systems.
From a practical standpoint, there's a huge base of legacy COBOL code running a lot of systems out in the world (many of them mission-critical) and it's likely cost-prohibitive to replace all of that software any time soon. The average COBOL programmer is probably nearing retirement age. Therefore one could reasonably assume that there will continue to be demand for new COBOL programmers for some indeterminate amount of time to come.
From a personal development/enrichment perspective, it certainly makes sense to study COBOL (and any number of other technologies both new and "less-new".). I'm not sure I'd put it near the top of my list, but its historical significance is reason enough to put it on the list. Somewhere.
My guess is that one of the reasons COBOL programmers (I'm a Fortran programmer, similar situation I suspect) are relatively secure is because they have oodles of experience; you won't get this from learning the language. Rather than ask how many COBOL jobs are there, ask yourself how often you see a COBOL job advertised. I think that it is much easier to hold on to one of these jobs than to get one.
And, of course, when one is advertised, you're in competition with all those very experienced currently-working-in-COBOL programmers.
Regards
Cobol developers are secure in their positions because their code makes money. It is not a horrible language to learn. Actually, it is rather nice once you grok the structure of it.
But it is only one tool in your tool box, you should have several.
I'd say it is not a complete nonsense to learn COBOL, as long as it is not the only technology you learn.

What are good "real" programming examples for a beginning programmer? [closed]

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I've been browsing Bjarne Stroustrup's new introductory programming book, Programming: Principles and Practice Using C++. It's meant for first-year university computer science and engineering students.
Early on in the book he works through an interesting extended example of creating a desktop calculator where he ends up implementing an arithmetic expression evaluator (that takes bracketed expressions and operator precedence into account) in a series of co-recursive functions based on a grammar.
This is a very interesting example, although arguably on the complex side for a lot of beginners.
I wonder what others thing of this particular example: would learning programming by seeing how to implement an expression parser excite and motivate you, or would it discourage you because of all the details and complexity?
Are there other good "real" programming examples for beginners?
When I was first learning to program, the best example I ever worked with was building a text adventure game from scratch. The basics just required knowing how to display text on the screen, receive input from the keyboard, and rudimentary flow control. But since text adventures always have room to add more features/puzzles/whatever, they can be easily adapted to explore aspects of whichever language you're learning.
Of course, not everyone finds games more interesting than calculators. It really depends on the programmer.
First, let me say that cognitive psychologists have proven in numerous studies that the most important factor in learning is desire to know.
If you want to learn about programming, you need to find a domain that stokes your desire to understand. Find a challenge that can be solved with programming.
I agree with the other folks when they suggest something that you are interested in. And games seem to be a common thread. As I reflect on my experience learning to program (too many years ago), math problems and a simple game was involved.
However, I don't think I really understood the power of software until I created a useful small program that helped a business person solve a real problem. There was a tremendous amount of motivation for me because I had a "client". I wasn't getting paid, but the client needed this program. There was sincere pain (gotta get my job done quicker) related to this situation.
So my advice is to talk to people you know and ask what small annoyance or computer-related obstacle to they have. Then try to fix it. It may be a simple web widget that reduces repetitive, manual tasks for an office worker.
One of my best early works was helping a little printing shop (no software, circa 1985) that struggled with estimating jobs to produce proposals that weren't money-losers. I asked alot of questions of the sales lady and of the operations manager. There was obviously an intersection of a common pain point with a really easy calculation that I could automate. It took me a couple of days to learn Lotus 1-2-3 (spreadsheet for you young-uns) enough to write a few macros. I was motivated. I had passion. I saw where I could make a difference. And that, more than anything else, drove me to learn some simple programming.
Having real people, real problems, and really simple solutions could be the inspiration you need as a beginning programmer. Don't try to write an accounting system. Just take one discreet piece of someone's frustration away. You can build on that success.
So, I wouldn't focus on the technique (yet). Don't worry about, "Am I doing this the most efficient way?" The main objective for a beginner is to have success, no matter how small, and build confidence.
BTW, that Lotus 1-2-3 set of macros grew into a full job tracking system. Very archaic, limited features, but made that little print shop much more profitable.
Create your motivation, fuel your desire, and develop your passion for programming like an artist unveils the masterpiece in a blob of clay. And be persistent. Don't give up when challenged with a roadblock. We all get stumped sometimes. Those are some of the best learning moments because humans learn more from failure than success.
Good luck.
I think making tiny games like text version of Tetris will be a good way of getting into pragramming world.
Board games are fun to design and code since they come in many shapes and difficulties
from tic-tac-toe to checkers to monopoly, its reinventing the wheel for educational purposes!
the best advice i can think of is to pick something from a field of interest you have because coding for the sake of coding might dim your resolve
Start small. Do examples that interest you. Stretch yourself just a little every time. Get comfortable with each step, to the point that you have confidence that you know what you're doing, and then try something a little harder the next time.
I think that any example program would help you learn a new language, but a beginner should try to work with something that is easy to understand in the real world, such as a mortgage calculator or something along those lines.
I think the answer is that it would depend on the person who is learning how to program.
One nice thing about something like an arithmetic expression evaluator is that it is a project that can start very small (make it work with just the format "X SYMBOL Y" where X and Y are single-digit numbers and SYMBOL must be a plus sign) and then you are slowly expanding the functionality to the point of a complicated system.
However, it might not be a great starter project for someone who doesn't really understand the concept of computers (hard disk, memory, etc.)
Try to think of something that you do on a computer that is repetitive, and could be easily automated. Then try to come up with how to make a program that automates that task for you. It can be anything, whether it's popping up a reminder every 15 minutes to stretch your legs or cleans up your temp directory on a regular basis.
The problem with this task is that it's conplex and not real life related. I don't need another calculator.
But once I had a CD with scratched surface near its center and lots of valuable JPEG files inside. I dumped the data from the unscratched part of the disk but all the filesystem was surely lost. So I wrote a program which analysed the dump and separated it into files. It was not very simple but was a nice and exciting file IO programming exercise.
Examples can be more complex than something you try to write yourself. It's easier to follow someone else doing something than it is to do it yourself. A real-world example like this calculator may be a fine way to introduce someone to a language. For instance, Practical Common Lisp starts with an example of an in-memory database (for CDs I think) and uses that as the springboard to explore parts of the language.
I prefer seeing a real example built up over time than just a lot of simple "Hello World" programs.
I've always found that implementing a game of some sort is sufficient incentive to learn various features of a language. Card games, especially, because they generally have simple rule sets to implement, but are sufficiently complex from an abstract point of view.
I would agree, though, with everyone else: find examples of things that interest you. Not everyone is a game fan, but something like a mortgage calculator would be far more interesting.

Pair Programming for a job interview [closed]

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Closed 11 years ago.
Our company has been thinking about scrapping our interview procedures and bringing each candidate in for a 4-5 hours sit-down with some of the programmers and just do some pair programming.
I like the idea in theory but I am not sure how you can really make it fair for each candidate. How would you rate them? Wouldn't their input really depend on what each programmer was working on that day?
Any thoughts on whether this is a good idea/bad idea or how to make it work is what I am kind of looking for here.
Cheers!
EDIT:
RESULT - AS requested
We are going to conduct the first steps of the interview the same as before. Phone followed by face to face. Instead of bringing them back for a third and final grilling, we are going to bring 3 developers back to sit with all 7 members of the team. We have decided to let the team decide who is then hired.
We have come to this conclusion for a couple of reasons. We believe this will empower the developers by giving them a choice who they are working. The second reason is group dynamic. We think it is really important to have a good group dynamic and it is hard to tell until after you hire a person if they will fit in or not.
So the end result is we are going to go ahead with the pair programming sessions but in a completely different way and for a completely different way than was originally intended.
Any thoughts or criticism of this approach is more than welcome!!
(this edit is posted as an answer below so feel free to downvote if you feel this is not the best approach)
Unless you use pair programming extensively in your real-world development, I'd be very hesitant to use this. I've met any number of high-quality professional developers who have mentioned a strong aversion to pair programming and whose skill would not be well-judged in such a process.
I hope you have a bunch of steps ahead of this one. For this to work you need an excellent resume and phone screen. You don't want to spend oodles of time on candidates that you shouldn't be talking to in the first place.
So you suggest an initial interview
and possibly have the second interview
as the pair programming session? – Ted
Smith (1 min ago)
Yeah. You might even think of having a simple coding interview happen over the web using something like CoPilot.
The easiest way is to give each person the same programmer to work with and the exact same piece of code.
The problem you're going to run into, is that hiring isn't like programming. There isn't a step by step process to lead to the right answer as to who to hire. (you can have multiple steps to make the decision easier). You have to evaluate each one on their strengths etc. and essentially make an educated guess as to which is the best one to hire. Sometimes you guess wrong.
The other thing about pair programming you're going to have to watch out for is the amount of time necessary to have each candidate at that stage go through that kind of a test. If I were looking for a job, I would be hesitant to go an interview at a company that would ask me to do that. Why? Because that is a lot of time, and if I am interviewing at multiple places, I could spend literally days just going to interviews for jobs I may not even get or want. Someplaces like Google or MS would be an exception, but most places are not like those two. (Not to mention the fact that if they are working on real code, you are essentially asking them to do someone's job for free).
As a personal anecdote, I got smacked around in an interview because of a technique like this. I had gone far in their interview process; passed the resume checks, the code submission and this was the face to face portion of the interview.
I was fresh out of university and had never pair programmed before nor done TDD. They sat me down to do a deck of card exercise and it flopped. Badly! I didn't understand why the interviewer was writing tests that seemed so dumb* (IE "return null;") and they didn't explain why and of course being foreign to TDD I didn't know what questions to ask. The end result was that it looked like I couldn't program my way out of a paper bag.
If you're going to do this type of exercise you need to cater to the interviewee because they're going to be in different spots with their aptitude. This means that you'll get different assessments that may not be based on actual talent and are thus going to be heavily biased.
**Now that I understand TDD, I do understand tests like this and how it's supposed to work, but man did that ever seem stupid at the time!*
I just had an interview with a San Francisco based company that prides itself on Agile methods/etc. I was to interview the CEO himself. I have about 20 years of experience in the industry, but have never pair programmed or developed using TDD approach. I was told it would be a "programming interview" but had not idea what to expect, and before we started the guy said that he thought that I may agree that all interviews should be done this way. (which in retrospect was nothing more than an arrogant statement).
Anyway, at the interview the exercise was to develop a class using TDD. It took me a second to adjust my thinking on the entire process, again since I had never pair programmed or done TDD. While I stumbled here and there I did ok in the end. but his reply was the I did not exhibit the aggressive back-and-forth nature that they require for their pair programming environment. Now, that could also have been an underhanded way of saying that "I didn't think you did great" kind of message.
Luckily I didn't need the job and to be honest the experience made me realize that I'd rather find a different career than having to be a software engineer that HAS to work in pairs, day in day out, when it came to developing code. Odd thing is that on occasion I have worked with another person on code simultaneously, so anything is possible.
In end I guess it was a good outcome since they didn't think I was a good fit and I didn't care for their working methods. But we would have came to the same conclusion had I talked a for a few minutes more about myself and had he given me a little more info on how they go about their work. Which is to say that there are other ways of finding a good fit candidate than putting them through the stress of pair programming with a complete stranger; bogus way to gauge competency imo.
One particular company uses a technique called extreme interviewing. For the extreme interview they will bring in say 30 developers and group them into 15 pairs. They will explain that they are looking for people who work well with others. That they will make a hiring decision based solely on their ability to work with others.
They will provide a problem for the pairs to solve. They will emphasis that they are not interested in the solution just each programmers ability to work with others. For each pair they will provide an observer of the pair. During the exercise (about 2 to 4 hours in duration), the observer will takes notes about a person ability to pair ... not the solution.
They are amazed how many programmers focus on solving the problem instead of collaborating. Of the 15 pairs, they will identify about 4 to 6 developers for a second interview. Those developers will be asked to come back and spend a week with the team (they get paid). After a week, they decide who to keep. Generally about half of them (2 to 3 developers).
When they are done, they have developers that are able to collaborate and after a week working with various pairs, the team has a strong indication who can effectively develop software. The process is both innovative and effective. They have had a high success rate with those they have hired.
I just had a pair programming interview a few days ago and to be honest, I don't really like it. I was notified of this a day just before the interview and then the interviewer told me that pair programming is what eventually I am going to do anyway in work. I went into the office and was paired up with someone who is a very senior software engineer. The company is in San Francisco and they are a well renowned company for pair programming, everyone pair programs in the office. At first it seemed to be fine, he explained about all the tools they used, their own unit testing framework that they build, and a bit of the project. He then basically wrote a bunch of unit tests and wanted me to work on the implementation to make it pass. Just as an FYI, the code base that already exists is huge, I would say 10k lines, it's not like a super complex project, but it is complex for someone to just step in and then write code without prior understanding of the class hierarchy etc. I find it really hard to believe that he expects someone to jump right away in a 10k line of source code that already exists. It just doesn't match for a pair programming interview, a smaller code base would help. I struggled a bit from navigating through the classes and going back and forth because I can't remember class names as I was overwhelmed by the amount of classes/code that already exists. To be honest, this really made me do horrible in the interview process. In the end I didn't feel really good about it. I haven't done pair programming before, mostly is just during assignments in my college year.
To me the power of pair programming can be harnessed if you're already proficient/comfortable with your pair, but is not really suitable for interview. Sometimes I would like to ask questions to my pair, but then I thought if I ask too much questions, then they would assume I were stupid and can't perform. If this was already on a real job, I wouldn't hesitate to ask, but in an interview it's hard.. you want to ask because your pair should help you out when you're stuck, but at the same time it's an interview, so you can't really ask much.
That is just my experience that I have from pair programming interview, my suggestion if you really want to do this:
be sure that you don't give the candidate to work with a large code base, work with a
smaller one and therefore he/she can show his/her skills to the max
be up front with the candidate before pair programming interview, can you ask questions
when you're stuck, should you be able to do this and that, what can't you do
be as detailed as possible
In the end, I wouldn't suggest it. It's hard to measure a candidate's performance in pair programming, and it might be biased as well.
I like this idea. However I think it might be difficult to do since it would require the candidate to have some knowledge of the project you would pair on with him. Also, 4 to 5 hours seems a bit long. What if you immediately see that it is not going to work out, are you going to sit through the whole session with the candidate?
Good question though. Stuff to think about.
Why not? Also, it's not like interviews are always (or ever) fair. You should evaluate the end results of the new approach against the traditional interview-based approach.
Also, a mini interview before the pair programming session might be good to keep from wasting the programmers' time with people who would be a bad fit.
From my limited experience, my feelings are mixed. I like the idea of pairing as part of an interview, esp. if the company uses pairing often, because it gives both a better feel for the fit. As a candidate, I've often gone through interviews where I sat in a room answering questions for a few hours, but afterward didn't have a good feel for what it would really be like to work in their environment. Pairing may be more beneficial than a random coding exercise, unless the interviewer is skilled at working someone through those. And I like being able to discuss technical stuff from both sides. And as a candidate, I'd rather interact with someone than just answer questions or solve code problems on my own.
But... as others have noted, the time needed can be an issue. I've gone through a couple days of pairing interviews and found some periods good, while others felt like a few hours were wasted: one because the developer wasn't working on something that lent itself to pairing (esp. given my background), the other because an env issue prevented much useful work for a while. If the job doesn't work out, it can be frustrating to have taken a day or two off work for this.
One place trying this approach wasn't sure if they should have someone outside the company working on a customer's project. They also worried that explaining the domain and work being done would take too long, though without that the candidate may not be able to contribute much. So they chose an open source project the employee was working on.
This seems to be a key point: there needs to be a well chosen task that the candidate can understand quickly and be able to contribute to. The latter part will depend somewhat on the candidate's skills. Also key would be the employee's ability to evaluate someone with this approach. Not everyone is great at normal interviewing, and that's probably more true of a pairing interview.
Also, if a company doesn't do much pairing then this kind of interview may not be as useful. There does seem benefit in seeing someone code (as Joel Spolsky notes), and this could be a good way to do that. But if pairing is not a typical part of the job, then perhaps a full pairing session isn't appropriate. Maybe a modified version.
I'd be curious what companies who have taken this approach think of the results. Reading some of the other answers to this question shows that it doesn't always seem ideal from the candidate's view.
To keep it fair, you'd have to make every participating staff member have a prepared problem to evaluate the candidate on. Preferably something taken form the real world in their company experience, but something that has already been resolved. This is a good chance to evaluate the knowledge on a problem and evaluate not just programming skills.
I hate it when too specific questions are answered. I had an interview once where a programmer was testing my knowledge of the STL which I used extensively and was trying to get me to answer that a custom allocator was needed. I had heard of them but never used them (esp in windows) and was made to feel dumb. IOW, avoid being judgmental.
So my point is, ask practical questions that aren't so much about testing programming knowledge as you can evaluate more qualitative personality and problem-solving approaches if you use the "pair programming" idea.
Good question!
Honestly, that sounds like a great idea, though Jason Punyon is certainly right that you should do a lot of weeding before you waste significant amounts of your developers' time on culls. You get a glimpse at an important metric out of it that's otherwise nearly unobtainable in interviewing: what someone's like to work with.
I don't think there's really any need to be concerned about it being "fair" based on the subject matter or trying to present consistent situations to different candidates, if you maintain the right evaluatory attitude -- that it isn't about whether they "got the right answer" or jumped through the right set of hoops, but what sort of effort, problem-solving, communication aptitude and flexibility they showed. You'd lose most of the benefit of the exercise by turning it into an artificial test, not to mention changing it from something that your developers can get some benefit from (or at least still get some work done during) to a massive waste of their time.
Joel Spolsky has an excellent Guerrilla Guide to Interviewing which talks about, amongst other things, programming tasks.
Trivia: Joel Spolsky is a co-founder of stackoverflow.com

is a great memory a requirement for great programming [closed]

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Do you think having a great memory is REQUIRED to be a great programmer?
I don't consider myself a great programmer but I do think I am decent. But my memory is REALLY bad so I find myself always having to remind myself how to do things. I mean I "know where to look" but sometimes it makes me feel like I am just a crappy programmer. What makes it even worse is that I am always forgetting where things are in my source code or what algorithm I used for certain situations.
Think back on the great programmers you have encountered in your life, didn't all of them seem to have amazing memories?
Surely apocrapful, but here's Einstein's number:
A reporter interviewed Albert
Einstein. At the end of the interview,
the reporter asked if he could have
Einstein's phone number so he could
call if he had further questions.
“Certainly” replied Einstein. He
picked up the phone directory and
looked up his phone number, then wrote
it on a slip of paper and handed it to
the reporter.
Dumbfounded, the reporter said, "You
are considered to be the smartest man
in the world and you can't remember
your own phone number?”
Einstein replied, “Why should I
memorize something when I know where
to find it?”
I have this coworker that writes really bad code that is incredibly hard to maintain. I've come to the conclusion that his problem is good memory. He's simply able to remember where he put what functionality. Therefore he doesn't have to write code that is self-explanatory. He simply remembers that crap. The rest of us have a really hard time figuring out his code.
I'm sure that good memory isn't that guys only problem. But I'm sure his code would improve if his memory got worse.
Treat your short term memory as stack (not static) and don't expect much more from it. I've come back to code that I wrote only a month ago and its almost like someone else wrote it .. it just takes a while to get back in the same zone.
I get teased, often for leaving comments for myself like breadcrumbs .. but it works. If I finish some function and say "AHA, that is absolutely BRILLIANT!", I immediately comment my complexity as I'm sure to forget.
So now, to answer a question with two questions:
What did you have for lunch last Wednesday?
What is the purpose for 'counter' in hash_foo() ?
At least, with #2, you can quickly go back and look / remember.
As long as you can remember how g-o-o-g-l-e is spelt, you're fine. :)
But seriously, you do need to keep several things in yoru short term memory at once. Longer term memory is I think less important. As long as you're aware that something exists, you've seen something before, etc then when it becomes relevant you'll know you can dig it up.
Experienced programmers can generally regurgitate APIs, minor details and so forth but in my experience this has never been a case of sitting down and memorizing things by rote. It's a natural consequence of using things again and again.
I would say the opposite, having a good memory may lead to writing code which only the author can understand, because she remembers the details of its logic. On the other hand I, having bad memory, document my code and write it as clear as possible.
Honestly, I've found poor memory to be an asset, even poor short term memory. Poor short term memory really forces you to break out the separation of concerns. The end result is very clean, very simple, very well encapsulated code. I actually have pretty good short term memory, but I've learned to try really hard not to employ it after a few experiences writing code while I was distracted enough that I couldn't really retain much at once. I was actually shocked to observe that the code was actually far cleaner than code I'd developed im the past.
Poor long term memory is an asset, because you end up training yourself very well on how to find and learn techniques, API's, algorithm's, etc. It also tends to encourage you to find a small set of common themes to guide you in your work.
All in all, the mark of a good programmer isn't complexity (which is really difficult to achieve without good memory), but simplicity (which by nature doesn't require much memory).
I can answer exactly this using just one word: NO. Having great memory to memorize all about programming is not a must. Experiences and the tedious learning by practice are the best.
I also have experienced this. If you have enough experience hours (or can be years) creating softwares with best practices applied, then you're a truly master on your own job or on programming languages you use to create softwares. Please don't be sad if you have bad memories, but striving to always learn and practice can defeat your memory weakness.
To me, there are two kinds of programmers in the world. The first were born to do it, the second learnt. In both groups they range from unbelievably poor to unbelievably great. Does memory denote those ratings? No, absolutely not. While a good memory can help you with learning, nothing helps you more than practice and understanding. After all, being able to remember the entire Encyclopaedia Brittanica means nothing without understanding. My server's storage is a classic example there.
Programming is about logic, both in the code and how you approach the problem. If you want clear, easy to understand code then chances are you'll break the problem into small manageable chunks (i.e. that fit in your head in their entirity) and work on each one. Each function then condenses down into a single command for your next stage of complexity. At the end of that next stage, if there is another, you'll have a set of single commands again to build on. Logical naming, logical partitioning, logical assembly... I think I'm getting my logical point across ;)
My memory is appalling, and I mean appalling. I can be introduced to 3 people and by the time #3's name is said I've forgotten who #1 is. I can still write some good code, not everytime or everyday; when you're in the zone it's something else, at that point it is art. So, put your memory to one side, get yourself either a really quiet space or a pink noise generator and dive in. The only thing that's going to make you a better programmer is practice, practice, practice. The only thing to remember is that programming is a skill and skills are practiced, and best practiced among friends who can give constructive criticism and advice... like Stack Overflow :)
Apologies for the tome level of this answer but I couldn't remember what I'd already written ;)
Having a good memory is quite useful but certainly not required. I would say that it's not that great programmers have a great memory but rather, they have spent a lot of time investigating even the littlest issues which improved their understanding and improves recall. If you spend 4 minutes resolving a problem (Googling or asking in SO) then you probably won't remember the resolution when you hit it again 4 months down the line. IT could be an evolutionary trait or just a bad memory =)
Good programmers also have well thought out principles which allows them to work on auto-pilot without second-guessing themselves. A good set of principles also achieves consistency and predictability (which is a quality of memory) through reinforcement.
This also extends into other domains. Chess grandmasters can recall an entire game played 40 years ago. That's because they remember patterns (openings, variations, root cause and effect of moves which led to the end game, etc). which helps group individual moves into units.
In software, tools can like auto-complete or having a KB/Wiki and searchable check-in history etc can help.
No. But maybe it can make you great...
An art of programming (maybe the art) is being able to approach problems in such a way that you can grasp the whole of them, despite your limitations (such as imperfect memory). This is because everyone - including the smartest of us - has limitations. Bumping into your limitations is not a sign that you have limitations, but a sign that you are reaching further.
This art (insofar as I know it) includes things like divide and conquer (using modules of various kinds, to match the shape of the problem); using standard techniques to telegraph your intention (idioms, OO Design Patterns are just one); separating out the core of the problem (this one is not about the code: it's about the problem); and of course comments.
I used to believe that good code was self-documenting (and even, that code is truth), but recently I'm writing parsers, and including the CFG in a comment is a very helpful reference, because it is a much simpler representation of the intention of the code.
A coder's gotta know their limitations. It's unrealistic to expect to have the same grasp of something months later, as when you were in the thick of it. All the above involve accepting that problem, and working on a solution. Not only does it make your code easier for you to grasp later on, it makes it easier for someone else to grasp... but most importantly I firmly believe that clearer and simpler code is fundamentally, and transcendentally, better code.
The competent programmer is fully aware of the strictly limited size of his own skull; therefore he approaches the programming task in full humility, and among other things he avoids clever tricks like the plague. - Dijkstra
In allusion to Edsger Dijkstra, a competent programmer is fully aware of the limited size of his own skull. The more details you don't cram in your head, the better you can tackle the problem at hand.
Modularize your code very much, refactor code, package your nifty algorithms to objects, and use those objects, in that way, you don't always have to "micro-remember" each and every implementation details of your programs.
No. The ability to forget about what you know and continue learning is at least equally important in the long term.
Good notes and bookmarks and web searches go a long way.
Remembering the really simple things is required for great programming. Things as simple as "keep at it".
An interesting perspective from the other side of your monitor: Locality of Reference
I think one benefit to having a good memory (modesty point: I have a good memory) is the ability to be able to think on your feet when not actually in front of a computer.
For example, you might be in a meeting when some new kind of functionality for your app is suggested. Can it be done? How long is it likely to take? These are questions which are easier to answer if you can pretty much walk through 250k loc in your head.
That said, I find a grain of truth in others opinions that my own code might be less clear because I can remember it better.
Some of the best-written code I've ever seen was written in such a way that each design decision was inevitable, and the code read as its own explanation. That's far better IMHO than code which requires the reader (or, worse, the maintainer) to keep tons of arbitrary detail memorized.
My own index of complexity in code is "How much stuff do I have to keep in mind to understand this one line?"
More is worse.
I think having good memory is helpful for learning new things quickly.
This doesn't mean it is a requirement for being a great programmer.
In fact it is more about intelligence rather than memory capabilities, but it's too much of a complex subject to be able to identify certain qualities and compare them with programming skills, and be able to retrieve any relevant info.
That is the mystery of the brain.
Occam's Razor suggests that a simpler theory is likelier to be true.
If code is a theory, describing inputs going to outputs, then shorter code, using expected idioms and libraries, is more likely to be "true" - that is, it is more likely to capture the essence of the solution, so it will generalize to inputs that you didn't expect.
Shorter, unsurprising code is easier to remember.
It all depends on what your good memory remembers..
I've worked on the same project for 10 years or so and I can't remember every line and who wrote it and why.
But... I can remember pretty much all the user requests and user issues. Who wanted what and when.
I can remember pretty much all the support issues we have had.
Finding old code is easy - we have great tools for that. Finding old issues is a much more abstract process: we have JIRA and Wikis but sometimes they don't cut it because they fail to provide the semantic meaning.
So. Pay attention to what REALLY matters and remember that.
Programmers with poor memory are like Universal Turing machines compared to practical computers: technically you can accomplish the same things by referring to information you or someone else has recorded somewhere... it's just that it may take a little longer....
I think it's possible to be able remember different types of things with differing degrees of aptitude.
For example, I sometimes find I have a pretty bad memory when it comes to random facts and figures, as well as things that I've done or will be doing - the latter meaning I find bug-tracking software an invaluable tool.
On the other hand, I can remember the structure of complex pieces of software I've written, and where to find specific things within that.
This may be about logical association. Well-designed software should (in theory) have a logical structure, which may make it easier to store in your memory if your brain is wired up that way.
Random piece of information, however, may not have these associations, making them harder to remember.
I would say its necessary for being great and fast. My memory for programming details is OK (but I have google for that). However, when I sit in front of applications that I've primarily written (~30-40 k lines of code) I'm able to load its structure almost completely into my memory. I can find the way I'm doing something in a couple of seconds and recall why I implemented it the way I did. That's invaluable. By 11 am I've been able to do more work than some others do all day. Now, that doesn't make me a great programmer, but it does make me an enormously productive productive programmer. This gives me time to refactor, write extra code, surf SO, grab an hour lunch, etc.
Just a simple comment "Repetition is the mother of learning", it doesn't matter if you have a good/bad memory. The function you use more in your programs you will remember the best. Also, in my case, i have the internet, when i don't remenber something i just ask, even if it is a bumd or easy question, and a lot of times I remember the answer after I post the question and then I quickly post the answer. The problem is how much time you put your mind to work....
:)
I think it depends. Memory for a programmer is very very important. Both short and long term. However, what you use that memory for is the important thing. As a programmer, if you're using it to memorize ever nuance of an API then I'd say you're wasting your memory.
Ultimately, I try to use my memory to remember the important things and anything that I can't easily find at a later point in time. I'll usually put API stuff in short term memory and use google and intellisense to help me with the specifics. Design patterns, methodologies, lessons learned from experience, on the other hand are usually what I try to put into long term memory so I can use it effectively in the future without having to relearn everything.
In short, yes a programmer needs a good memory...both long and short term. But they need to be wise in how to use that memory...and that, I think, makes the difference in a great programmer.
Having a strong enough memory to hold the things you need to use today is the important part. If you are constantly searching for answers to the same question, you probably have a weak memory.
The most important thing is remembering where you can find the answers. I will sometimes blog on topics that are a bit more complex so I have a place to find them when I need them. But I don't try to hold onto them perpetually, because I can search my own blog and find them later. I do the same with other people's blogs and I know which blogs to hit for certain types of answers.
When all else fails, Google it!
I used to think having a good memory was a time saver because the more you remembered, the less time you spent looking things up, but tools and IDE have got so good now, many things that I used to memorize like syntax and various code snippets are quickly available in a few keystrokes. That, and the fact that the amount of information in the field grows way faster than any mortal programmer can keep up with, makes me think memory is less important any more. More important, is having good access and organization to useful information.

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