I'm about to take a C++ test. But I only get one crack at it to get over 85%. If I don't push over that, then I don't get the job.
The problem with these tests are that they typically target generic C++, and depending on what libraries you use your definition of generic may differ. STL and Boost may seem logical to some (and should be part of most) but I worked with MFC for years before ever using templates. Why use >vector> when you've got access to CArray? (retorical question)
If you've worked with dialogs you've not used stdio. If you've worked with Borland products you've not used MFC. If you've worked with Palm, you've not used the file system, and you've definitely not used CFile.
OK, so here's the question...
Given that I'd like to pass the 85%, I'm taking online tests of "generic" C++. So... Is there a place I could go to find tests? The more the better. Correct answers are also good, either during or after the test. As long as I can learn from my mistakes.
EDIT: If your answer doesn't have a link to a test, some C++ questions, or some interview questions... You missed the point of Is there a place I could go to find tests?
Great example.. I've just found this question.
What does the following code fragment print? cout << setw(6) << setfill('#') << "Hello";
I've been coding for 9 years. And never used cout, setw or setfill once. Not since university.
Erase all the MFC from your head for now. Go pick up a book like The C++ Programming Language, and try to learn the concepts front to back. You should be fine. If they are asking for more than this, I don't want to know what their definition of "generic" is.
The few times I've been "tested" (well "interviewed"), folks were far more concerned with questions like:
What is Object Oriented Programming? OOA (analysis)? OOD (design)? UML?
When should you inherit from a class? When should a class be aggregated?
What are virtual methods? What are pure virtual methods? What is the vtable?
Sibling cast problem. class C : public A, public B; C c; B * b = & c; How to cast object b (type B*) to an A*?
What does the stack look like as a simple program executes?
Differences between heap/stack?
How does new() differ from malloc()?
etc.
There's lots of previous discussion on C++ interviewing questions here on StackOverflow and elsewhere:
https://stackoverflow.com/questions/240212/
what-is-the-difference-between-newdelete-and-mallocfree
https://stackoverflow.com/questions/347793/
c-areas-you-look-for-during-interview
https://stackoverflow.com/questions/365823/
what-kinds-of-interview-questions-are-appropriate-for-a-c-phone-screen
http://www.joelonsoftware.com/articles/GuerrillaInterviewing3.html
Just to add my two cents here: If they are looking for graphic details... To see if you've memorized the entire C++ spec... Well I know the economy stinks right now but it is improving, there are other jobs out there, and you NEED to find one of them. Interviews are a two-way street. If they are into nit-picking details, this is NOT a place you want to work.
You might try Herb Sutter's book Exceptional C++; it contains items organized like questions and is, in my opinion, very clear and very well written. I don't know if it will be directly useful for the interview, but it makes you think about aspects of the language you had never considered before.
It's been a long time since I last visited it, but you might also try this site with interview questions: geekinterview.com - take a look in particular at the C++ section.
All the best for your interview :)
What does the following code fragment print? cout << setw(6) << setfill('#') << "Hello";
It prints the following sentence to standard output:
Please do not work for us. We have no clue about what it means to be a
good software developer.
I found these.
http://www.acuit.com/_vti_bin/shtml.dll/Test_C++.htm
http://www.acetheinterview.com/questions/cats/index.php/algorithm
http://www.faqs.org/faqs/C-faq/faq/
http://www.coolinterview.com/type.asp?iType=41
http://www.radiussg.com.au/Candidate%20Interview%20Guide.pdf
http://www.eecs.utoledo.edu/~ledgard/oop/left.html
Some questions in FAQ's might work as tests.
IF you are going to give tests for job then brainbench tests may help.
I guess C++ tests are free and you can get some idea of what kind of questions you can get.
Good luck for tests!
During interviews I bother about the candidate being able to show me that he/she understands what he's/she's doing and that he's/she's leaning toward "modern" C++ (i.e. template intensive).
He/she also needs to understand some subtilities of the languages, but not the most arcane. I don't ask tricky question that are based on the oddities of the language. Why?
STL mastery is a pre-requisite. I see knowing nothing about Boost as a bad sign.
If I were to write a test, I would make it quite easy just to filter the really bad programmers that don't master the syntax and the logic of C++. I however prefer a one hour one-to-one interview to filter candidates.
If you find yourself fighting against a very hard written C++ test : run away.
I hope this helps.
Edit : if you really want tests and questions, check this out : http://www.gotw.ca/gotw/
There are a few free tests here and they have explanation videos on youtube for a few of the questions.
Related
For reasons I will spare you, I have two weeks to learn some C++.
I can learn alone just fine, but I need a good source. I don't think I have time to go through an entire book, and so I need some cliff notes, or possibly specific chapters/specialized resources I need to look up.
I know my Asm/C/C# well, and so anything inherited from C, or any OOP is not needed.
What I do need is some sources on the following subjects(I have a page that specifies what is needed, this is basically it, but I trimmed what I know):
new/delete in C++ (as opposed to C#).
Overloading cin/cout.
Constructor, Destructor and MIL.
Embedded Objects.
References.
Templates.
If you feel some basic C++ concept that is not shared with C/C# is not included on this list, feel free to enter those as well. But the above subjects are the ones I'm supposed to roughly know in two week's time.
Any help would be appreciated, thanks.
Edit: I want to clarify - I don't expect to study for two weeks and then go and write Quake.
I need to get to a level where given some code and a while to think about it, I can understand it. nuances like ++X vs X++ don't matter as much as knowing what the main keywords are, etc.
This site is your best bet. Although its a great reference anyway, the way the questions are phrased and organised you'll be able to get up to speed quicker:
http://www.parashift.com/c++-faq-lite/
I will be honest with you. In 2 weeks, you won't be able to learn the whole C++.
Let me rephrase that, because no one will ever know everything about C++ (it is very huge and yet it's still growing), you won't be able to learn everything you need to become an expert C++ programmer.
However, if you do have some good programming background, many concepts in C++ will sound familiar to you. This will help you learn complex concepts quicker than novice programmers.
I would suggest you to go to C++ FAQ Lite
because it is the site that lists all the main concepts of C++.
Don't expect to program something enterprisy after going through the site, because that ability comes after you have coded some extensive systems in C++. However, the site will definitely help you to understand what C++ looks like and other people deal with in C++.
GOOD LUCK :)
Thinking in C++, Volume II. Free, well written and available online.
http://www.mindview.net/Books/TICPP/ThinkingInCPP2e.html
I know you said you didn't want to read a book but "Accelerated C++" is probably what you want. It was actually was used in like a 2 week crash course at Stanford from what I remember to get people up to speed on C++.
If you do not have time to go through an entire book, you may try an online tutorial such as the one at http://www.cplusplus.com/doc/tutorial/.
However, it will be useful to go into more depth about common pitfalls and good practice in C++. A good online resource for this is the C++ FAQ lite, at http://www.parashift.com/c++-faq-lite/ .
If you decide to buy or borrow a book, "Effective C++" by Scott Meyers would be a good choice. You do not need to read it front to back, as each chapter is dedicated to a specific problem you are likely to encounter when writing C++ code, and can be read separately.
If you need quick explanations of specific sections of the language, http://www.learncpp.com/ is also a good resource. The caveat is that their webserver is dog slow most of the time (which is unfortunate, because they have some really good explanations).
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I am new to work but the company I work in hires a lot of non-comp-science people who are smart enough to get the work done (complex) but lack the style and practices that should help other people read their code.
For example they adopt C++ but still use C-like 3 page functions which drives new folks nuts when they try to read that. Also we feel very risky changing it as it's never easy to be sure we are not breaking something.
Now, I am involved in the project with these guys and I can't change the entire code base myself or design so that code looks good, what can I do in this situation?
PS> we actually have 3 page functions & because we do not have a concept of design, all we can do is assume what they might have thought as there is no way to know why is it designed the way it is.
I am not complaining.I am asking for suggestion,already reading some books to solve the issues Pragmatic Programmer; Design portion from B.Stroustrup; Programming and principles by B.Stroustrup;
The best and most important thing you can do is lead by example. Do things the right way and try to improve things slowly. You aren't going to fix anything overnight.
Make sure every piece of code that you are responsible for is better after you are done with it. Over time, the system will tangibly be better because of your efforts.
After you build a strong reputation with your co-workers, try go start some code reviews or lunch-training sessions to get everyone up to speed on better ways to do things.
In a nutshell: it will be difficult and frustrating, but it's possible. Good luck.
Your best bet is to NOT to handle it at all. Here are potential problems if you try:
You will be criticized for doing something you were not told to (makes performance reviews go real bad.)
You will have less time to do your own work.
You will not advance your career by cleaning working code- if it is not broke then do not touch it.
Never make enemies with people who control your career- unintentionally implying they are obsolete morons does not help your cause (especially in a bad economy).
Focus on making your own code great. Battling poorly written code is part of the ill of being a Software Engineer. You are in the wrong profession if you will not stand for it.
A little off point but important- You may need to switch jobs or teams if possible once the economy picks up. Mixing with a truckload of bad coders who do not bother to update their knowledge and practices dulls your own programming skills and weakens your marketability.
If you're a junior dev, then the only thing you can really do is write code as elegantly and readable as possible.
If your style is indeed better, other people might notice and say "hey we should adopt this formula"
Actions speak louder than complaints, which is something I noticed.
The present is embodied in Hexagram 47 - K'un (Oppression): Despite exhaustion, there may yet be progress and success. For the firm and correct, the really great man, there will be good fortune. He will fall into no error. If he make speeches, his words cannot be made good.
The future is embodied in Hexagram 6 - Sung (Conflict): Though there is sincerity in one's contention, he will yet meet with opposition and obstruction. If he cherish an apprehensive caution, there will be good fortune. If he prosecute the contention to the bitter end, there will be evil. It will be advantageous to see the great man. It will not be advantageous to cross the great stream.
I was in the exact same shoes before. I got hired as a C++ programmer to 'lead the team' on how to use C++ by an enthusiastic manager. That was about a decade ago. Some of the newer engineers loved me, the seniors despised me. Our system was basically a pseudo-C++ system. It was like C with classes, but it appeared that people didn't even understand the usefulness of things like constructors since they hardly appeared.
You complain about functions that are 3 pages long; we had functions that were 8000 lines long full of long jumps, function pointer casts, etc. One of the seniors even formatted the code with 2-space indentations so that super deep nested blocks can be written without using much horizontal space since the seniors seemed to be allergic to writing functions and procedural programming in general. Someone even inlined a 2000 line function thinking it would make things faster. You might be dealing with some bad code, but I was dealing with the most horrid copy-and-paste code imaginable.
Unfortunately I was very young and cocky. I didn't get along with the seniors, I fought against them in territorial battles over code. They responded by creating coding standards which no sane C++ programmer could follow (ex: it's okay to use operator new, but don't use exception handling, don't use constructors or destructors, etc). As a result I wrote the most bizarre and stupid standards-workaround C++ code just to kind of rebel against those standards since I refused to write C-style code given the reason I was hired (I didn't hate C so much, but writing C code was not part of the job description: I was hired essentially as a C++ consultant), even though the standards made C-style coding the only practical way to do things. I only kept my job because I put in so much overtime to make sure that my code works very well in spite of these ridiculous coding standards.
It wasn't until years later when others started to see things my way that we lifted the silly standards and started writing more natural, easy-to-read C++ code complete with STL and boost goodies, RAII, exception-handling, etc. That isolated the seniors who refused to write code in a more sane fashion and they were finally forced to adapt.
In retrospect, I could have done things much better. The seniors were intent not to allow me to be put in a teaching position, but I think I would have gotten my point across much faster with my head down. The biggest regret I have is trying to work around the impossible coding standards rebelliously rather than getting them rectified through clear and rational discussions. As a result, I have really stupid and obfuscated C++ code in the system which people attribute to me even though that's not how I normally write C++ code. The regular developers I work with understand this, but the seniors still point to it as an example of why C++ is bad.
In short, I recommend that you focus on making more friends rather than enemies. Your friends will support you, and if your way is better and you can clearly demonstrate it, you can isolate the few who will never agree.
Being enthusiastic to code the right way is a good trait to possess and in the software industry we will always encounter other developers who write code that is not quite in line with our "perfect way" of coding. This should never be interpreted as rubbish code, or inept coders, because we all start out like that in some shape or form.
Always respect your peers around you as you want them to respect you. It's certainly not easy to do in an environment that highly regards ego, but attempting to approach a topic like this is never easy.
It's how you communicate
Try different approach angles, remember you are there to learn as much as to render a service.
So commenting on the "poor" code style in an "in-your-face" kind of approach might not be the result you were looking for. So then back up a bit and try approaching the topic with "I was considering the style of code used and have a few suggestions..." and see the difference that gives.
Where I work now, the one thing I've learnt is that it's fine to comment on something that's might not be good quality but then I had better have a better solution to present.
In other words, be prepared to back up your words with useful solutions and not because you feel so.
This is the most basic reason why establishing coding standards and code review processes are a good idea.
I will not write three page functions no matter what coding standards and processes are established, but some people will. They will create 20 local variables at the beginning, without initializing any of them. You'll have pointers and integers with unspecified values. You won't know the exact meaning and scope of each variable. Etc etc.
Try to convince your manager and, later, your team, with solid arguments. Maybe you could start with a shared reading of Effective C++ or C++ Coding Standards. Try to stress the point that, when working this way and creating better code, everybody wins. If they see this as a win-win situation, they will be more open to the change.
I can empathize.
I'm below two senior programmers who have very unique styles that I find frustrating. We have code that consists of one main function that's 1000 lines long. (That is not a typo.) Our coding standards discourage globals, so we make every program one App object. Now our globals are member variables! When we need an iteration interface for C++ classes, why should we use the begin, end, and operator++ conventions, when First, AtLast, and Next can be used instead. We've wrapped up third party libraries in custom interfaces for no good reason. (We've wrapped log4cxx and lost functionality for no reason I can tell, and one of our date classes consists of a shared pointer to a boost::date object with a fraction of the functionality.)
Here's how I've kept my sanity. I've focused on the new languages and tools. This is our company's first project involving Python, and I've spent my time writing utilities and programs there. While the senior programmers code in what they're familiar with, I've got near free rein of all the Python code. I couldn't stand the C++ APIs we use, so I duplicated most of the same functionality in Python in a much more friendly way, and the other developers prefer it too.
Likewise, we have little familiarity with log4cxx and less with boost-build, both of which I've taken time to study in depth and know good enough that people come to me with questions. I've written a handful of resources on our wiki giving usage tips for log4cxx and numpy and other tools.
This is how it is, get used to it or quit and find a place where it isn't like that. You will be marginalized if you criticize their efforts and they may feel threatened if you do indeed write your own, better code or improve theirs. At the end of the day they deliver code and management sees a black box that works and that's all that matters. Plus, you'll be just another kid from college who thinks he knows something about development at a business and laughed at and ostracized when not around. Honestly, a lot of the times these systems are built like this because of shaky requirements, lots of functionality bolted on with time and managements lack of respect for a stable software development process.
Not all companies are like this. I'd start looking for a new job to be honest.
I fervently hope, this is the best opportunity to grow by facing the challenge.As Robert said,try to lead by example.If possible let them adopt your pattern.
You are not alone. I too faced recently, luckily we have support from Senior Management for Code Reviews.
1. Even a single line change for Bug fix should be reviewed online.
Comments on code can be classified as CodingStandard/Suggestion/Clarification/Major/Minor etc
While giving comments to senior you can start with Clarification/CodingStandard rather than Major
You could address the issue of "we are afraid to touch it for fear of breaking it" by writing extensive unit tests. Once you get the unit tests in place, you will be freed to refactor at will. If your unit tests still pass after the refactoring, you can be confident you haven't broken anything.
Just place a copy of "Clean Code" (Martin), "Refactoring: Improving the Design of Existing Code" (Fowler) or "Effective C++" somewhere in the office where people may start browsing the books. From now on, word will spread. Seriously, its never too late to learn! ;)
I have to interview some C++ candidates over the next few weeks and as the most senior programmer in the company I'm expected to try and figure out whether these people know what they are doing.
So has anybody got any suggestions?
Personally I hate being left in a room to fill out some C++ questions so I'd rather do a more complex test that I can chat with the interviewee about their approaches and so forth as we go along. ie it doesn't matter whether they get the right answers or not its how they approach the problem that interests me. I don't care whether they understand obscure features of the language but I do care that they have a good solid understanding of pointers as well as understanding the under lying differences between pointers and references. I would also love to see how they approach optimisation of a given problem because solid fast code is a must, in my opinion.
So any suggestions along these lines would be greatly appreciated!
I wouldn't make them write code. Instead, I'd give them a couple of code snippets to review.
For example, the first would be about design by contract: See if they know what preconditions, postconditions and invariants are. Do a couple of small mistakes, such as never initializing an integer field but asserting that it is >= 0 in the invariant, and see if they spot them.
The second would be to give them bool contains(char * inString, char c). Implement it with a trivial loop. Then ask whether there are any mistakes. Of course, your code here does not check for null in the input parameter inString (even if the very previous question talked about preconditions!). Also, the loop finishes at character 0. Of course, the candidate should spot the possible problems and insist on using std::string instead of this char * crap. It's important because if they do complain, you'll know that they won't add their own char *'s to new code.
An alternative which addresses containers: give them a std::vector<int> and code which searches for prime numbers or counts the odd numbers or something. Make some small mistake. See if they find any issues and they understand the code. Ask in which situation a std::set would be better (when you are going to search elements quite systematically and original order of entrance doesn't matter.).
Discuss everything live, letting them think a couple minutes. Capture the essence of what they say. Don't focus on "coverage" (how many things they spot) because some people may be stressed. Listen to what they actually say, and see if it makes any sense.
I disagree with writing code in interviews. I'd never ask anyone to write code. I know my handwritten code would probably suck in a situation like that. Actually, I have seldom been asked to do so, but when I have, I haven't been hired.
This one is a great complex task, even though it is looking quite harmless.
I believe that a C++ programmer needs more than just generic programming skills, because...
In C++ it's harder to shoot yourself in the foot, but when you do, you blow off your whole leg.
Writing bug-free, maintainable C++ code places a much higher demand on a few areas than most languages.
One thing I'll call "pedanticness". You know how some people can spot spelling errors in something at a glance? A C++ programmer needs to be able to spot simple bugs while they read or write code (whether the code is their own or not). A programmer who relies on the "compile and test" technique just to get rid of simple bugs is incompatible with the C++ language, because those bugs don't always lead to immediate failure in C++.
C++ programmers also need a good knowledge of low-level stuff. Pointers, memory allocators, blocking, deadlocks. And "nitty gritty" C++ issues, like multiple inheritance and method hiding and such, particularly if they need to maintain other people's code.
Finally, C++ programmers need to be able to write code that's easy for other people to use. Can they design stuff well?
A good test for the first two areas is "Here's some C++ code I got off the internet. Find the bugs, and identify the unneccessary bits." (There's lots of really bad C++ code available on the internet, and often the programmer does unnecessary things due to a faulty understanding of how to be "safe" in C++.)
The last area you can test with more generic interview questions.
A few questions can allow you to know a lot about a candidate:
Differences between a pointer and a reference, when would you use each?
Why would you make a destructor virtual?
Where is the construction order of a class attributes defined?
Copy constructor and operator=. When would you implement them? When would you make them private?
When would you use smart pointers? what things would you take into account to decide which?
Where else have you seen RAII idiom?
When would you make a parameter const? when a method?
When would you make an attribute mutable?
What is virtual inheritance?
What is template specialization?
What are traits?
What are policies?
What is SFINAE?
What do you know about C++Ox standard?
What boost libraries have you used?
What C++ books have you read? (Sutter? Alexandrescu?)
Some short exercises (no more than 10 minutes) about STL containers, memory management, slicing, etc. would also be useful. I would allow him to do it in a computer with a ready environment. It's important to observe the agility.
Checkout Joel's Guerrilla guide to interviewing. Seems a lot like what you are looking for.
"Write a program that receives 3 integers in the range of 0..2^32-1, and validates if they represent valid edges of a triangle".
It seems to be a simple question. The input is considered valid if the sum of any two edges is greater than the third edge. However, there are some pitfalls, that a good programmer will handle:
The correct type to use should be unsigned long. Many "programmers" will fail here.
Zero values should be considered as non-valid.
Overflow should be avoided: "if (a+b <= c) return false" is problematic since a+b may cause an overflow.
if (a <= c-b) is also bad solution since c-b may be negative. Not a good thing for unsigned types.
if (c > b) { if (a <= c-b) return false; } else { if (a <= b-c) return false; } This looks much better, but it will not work correctly if (a >= b+c).
A good programmer must be detail oriented. This simple exercise will help checking if he is.
Depending on what your organisation's pre-screening is like, assume that the person knows nothing at all about C++ and has just put in on their CV because it makes them look supertechnical. Seriously. Start with something simple, like reversing a string. I have had candidates who couldn't even write a function prototype for this !!
Do not forget to also test for code bigotry. I know I don't want anyone working for or with me that isn't a flexible and consequently practical programmer both in their attitude to the programming language, but also in their approach to problem solving.
Denying any type of preconceptions
Understanding the value of the
exceptions in any Best Practices
Being capable of refusing long term
habits in favor of something else if
the need arises
These are characteristics dear to me. The manner of testing for these is not ideal if the interviews aren't lengthy or don't involve presenting code. But showing code snippets with purposely debatable techniques while offering a use case scenario and asking the candidate how they feel about the solution is one way.
This article offers some general ideas that are relevant regardless of what language you're working with.
Don't test only the C++ and overall technical skills! Those are of course important, but they are nothing if people don't listen, don't answer properly or don't follow the commitments they made.
Check at most for the ability to clearly communicate. If people cant tell you what roughly they did in their former jobs within a few minutes, they will also be unable to report about their work at your place etc.
In a recent company we invited people for interviews in groups of about 3 people together. They were surprised, but nobody was angry about that. It was very interesting, because people had to communicate not only with us, but also with others in the same position. In case we were interested further, we arranged a second interview.
You can choose potentially problematic task and see how they approach it. Ask them to write a smart pointer for example, you'll see if they understand pointers, references and templates in one step :) Usually they are stressed so they will do mistakes, those mistakes might help you find out how good they problem solving skills are, what paths would they use to fix a mistake and so on. The only problem with this approach is that sometimes interviewee just don't know anything about the task and you would have to quickly figure out something easier. If they do perfect code you can discuss their choices but when there's nothing to look at it is depressing for both of you.
Here is my answer to a similar question geared towards C#, but notice that my answer is language agnostic. My interview question is, in fact, in C. I rarely interview a person with the goal of finding out if they can program. I want to find out if they can think, problem solve, collaborate, communicate, understand something new, and so on. In the meantime, I circle around trying to see if they "get it" in terms of the big picture of software engineering. I use programming questions because that's a common basis and an easy ruse.
Get Codility.com to screen out non-programming programmers, this will get you a limited number of mostly reasoable candidates. Sit for an hour with each of them and try to build something together (a micro web server, a script for processing some of your data, a simple GUI). Pay attention to communication skills, i.e. how much effort does it take to understand the candidate. Ask the candidate for recommendation of books related to the subject (C++ software development in your case). Follow Guerilla Guide to Interviewing, i.e. answer yourself honestly, if the person is smart and gets things done. Good luck.
Check 10 C++ Interview Questions by Tests4Geeks.
It's an addition to their pre-interview C++ test and it has really usefull questions. Many people have been working on these interview questions so it's quite balanced and has no tricky or syntax questions.
Idea is quite simple - first you weed out incompetent candidates using the test, then you use article questions in real-life interview.
Whatever you do, pairing would be a good idea. Come up with a good program and pair with the guy and work towards solving the problem. IMHO, that a very good idea
So has anybody got any suggestions?
I'd recommend getting a copy of this:
http://www.amazon.co.uk/Programming-Interviews-Exposed-Secrets-Programmer/dp/047012167X/ref=sr_1_1?ie=UTF8&s=books&qid=1252499175&sr=8-1
ie it doesn't matter whether they get the right answers or not its how they approach the problem that interests me
You could ask the candidate to come up with a UML design to a common problem. If they show you a design pattern, then you can talk through the pros/cons of the pattern. You could then ask them to produce some code for one of the classes.
This would help you determine their technical knowledge level and their communication abilities.
I do care that they have a good solid understanding of pointers as well as understanding the under lying differences between pointers and references
Linked list problems are good for determining whether a candidate has a solid grasp of pointers.
As for references, you could show them some code that does not use references correctly, and ask them to describe the problem.
e.g show them a class definition that contains a reference member variable, and the implementation of the constructor with the reference initialization missing.
I would also love to see how they approach optimisation of a given problem because solid fast code is a must, in my opinion.
I'd start off simple...
Show them a code example that passes strings to a function by value. (the strings should not be modified in the function). You should check they correct the code to pass the strings by const reference.
After this, you could show a constructor that uses assignment instead of initialization (for objects). Ask them to improve it.
Lastly, ask them simple questions about data structure selection.
e.g. When they should use a list rather than a vector.
If you feel they have a grasp of the fundamentals you could either ask how they approach optimization problems (discuss profilers etc), or ask them to optimize something less obvious.
Take a look into this C++ test. They have a questions about differences between pointers and references as you require.
Here is full list of topics:
Fundamentals: References & Pointers, Const Correctness, Explicit
Standard Library
Class Design, Overloading
Virtual Functions, Polymorphism, Inheritance
Memory Management, Exception Safety
Miscellaneous: Perfect Forwarding, Auto, Flow Control, Macros
These guys are really serious about their questions, they also made the great list of C++ interview question which you might ask your candidates:
https://tests4geeks.com/cpp-interview-questions/
I am a new to professional development. I mean I have only 5 months of professional development experience. Before that I have studied it by myself or at university. So I was looking over questions and found here a question about code quality. And I got a question related to it myself. How do I increase my code understanding/reading skills? Also will it improve the code quality I will write? Is there better code notation than Hungarian one? And is there any really good books for C++ design patterns(or the language doesn't matter?)?
Thank you in advance answering these questions and helping me improving :)
P.S. - Also I have forgot to tell you that I am developing with C++ and C# languages.
There is only way I've found to get better at reading other peoples code and that is read other peoples code, when you find a method or language construct you don't understand look it up and play with it until you understand what is going on.
Hungarian notation is terrible, very few people use it today, it's more of an in-joke among programmers.
In fact the name hungarian notation is a joke itself as:
"The term Hungarian notation is
memorable for many people because the
strings of unpronounceable consonants
vaguely resemble the consonant-rich
orthography of some Eastern European
languages."
From How To Write Unmaintainable Code
"Hungarian Notation is the tactical
nuclear weapon of source code
obfuscation techniques; use it! Due to
the sheer volume of source code
contaminated by this idiom nothing can
kill a maintenance engineer faster
than a well planned Hungarian Notation
attack."
And the ever popular linus has a few words to say on the matter.
"Encoding the type of a function into
the name (so-called Hungarian
notation) is brain damaged—the
compiler knows the types anyway and
can check those, and it only confuses
the programmer."
- Linus Torvalds
EDIT:
Taken from a comment by Tobias Langner.
"For the differences between Apss Hungarian and Systems Hungarian see Joel on Software".
Joel on Software has tips on how to read other people code called Reading Code is Like Reading the Talmud.
How do I increase my code
understanding/reading skills?
Read read read. Learn from your mistakes. Review answers on SO and elsewhere. When you can think back on a piece of code you wrote and go "aha! I should've done xyz instead!" then you're learning. Read a good book for your language of choice, get beyond the basics and understand more advanced concepts.
Then, apart from reading: write write write! Coding is like math: you won't fully grock it without actually solving problems. Glancing at a math problem's solution is different than getting out a blank piece of paper and solving it yourself.
If you can, do some pair programming too to see how others code and bounce ideas around.
Also will it improve the code quality
I will write?
See above. As you progress you should get more efficient. It won't happen by reading a book on design patterns. It will happen by solving real world problems and understanding why what you read works.
Is there better code notation than
Hungarian one?
It depends. Generally I avoid them and use descriptive names. The one exception where I might use Hungarian type of notations is for UI elements such as Windows Forms or ASP.NET controls, for example: using btn as a prefix for a Submit button (btnSubmit), txt for a TextBox (txtFirstName), and so on but it differs from project to project depending on approach and patterns utilized.
With regards to UI elements, some people like to keep things alphabetical and may append the control type at the end, so the previous examples become submitButton and firstNameTextBox, respectively. In Windows Forms many people name forms as frmMain, which is Hungarian, while others prefer naming it based on the application name or form purpose, such as MainForm, ReportForm, etc.
EDIT: be sure to check out the difference between Apps Hungarian and Systems Hungarian as mentioned by #Tobias Langner in a comment to an earlier response.
Pascal Case is generally used for method names, classes, and properties, where the first letter of each word is capitalized. For local variables Camel Case is typically used, where the first letter of the first word is lowercase and subsequent words have their first letters capitalized.
You can check out the naming conventions and more from the .NET Framework Design Guidelines. There is a book and some of it is on MSDN.
And is there any really good books for
C++ design patterns(or the language
doesn't matter?)?
Design patterns should be applicable to any language. Once you understand the concept and the reasoning behind that pattern's usefulness you should be able to apply it in your language of choice. Of course, don't approach everything with a "written in stone" attitude; the pattern is the goal, the implementation might differ slightly between languages depending on language features available to you. Take the Decorator pattern for example, and see how C# extension methods allow it to be implemented differently than without it.
Design Pattern books:
Head First Design Patterns - good beginner intro using Java but code is available for C++ and C# as a download (see "book code and downloads" section on the book's site)
Design Patterns: Elements of Reusable Object-Oriented Software - classic gang of four (GOF)
Patterns of Enterprise Application Architecture - Martin Fowler
If you're looking for best practices for quality coding in C++ and C# then look for the "Effective C++" and "More Effective C++" books (by Scott Meyers) and "Effective C#" and "More Effective C#" books (by Bill Wagner). They won't hold your hand along the way though, so you should have an understanding of the language in general. There are other books in the "Effective" series so make sure you see what's available for your languages.
I'm sure you can do a search here for other recommended reading so I'll stop here.
EDIT: added more details under the Hungarian Notation question.
I can't speak for everyone else, but in my experience I've found that the best thing I learned about making readable and/or in general better code was reading (and ultimately cleaning) a lot of other people's code. Some people may disagree with me but I think it's invaluable. Here's my reasoning:
When you start programming, its difficult to determine what is crap vs. not crap vs. good. Being logical, rational and extremely intelligent help in making good code, but even those factors don't always contribute. By reading others works and doing the dirty work, you'll have gone through the experience of what works and what doesn't. Eventually, you'll be able to mentally navigate those minefields that others had to cross and you'll be prepared to avoid those identical minefields.
By reading other's works, you gain insight into their mind and how they tackle a problem. Just from an architecture or technique aspect, this can be very useful to you whether their
tactics were good or bad. By reading other peoples successful or unsuccessful implementation, you've gained that knowledge without putting in the actual time it took them to learn it.
Design patterns are extremely useful. Only time and experience with them will help you in knowing what the appropriate pattern for whichever problem. Again, read other peoples' code for this if they've successfully built some pattern that may be useful for you.
When dealing with extreme problems where people's work falls short, you learn to research and dive into the internals of whatever system/language/platform/framework you're working with. This research ability on your own is very useful when all else fails. But you'll never know when to start looking or for what until you get through the crud of other people's work. Good code or bad, it's all valuable in some form or fashion.
All these notations and formats and nomenclature are helpful, but can be learned or implemented rather quickly and their payoff is fairly substantial. By reading code from other people, you'll develop your own style of logic. As you encounter other peoples work and the tremendous amount of effort it takes to read through, you'll learn what logical pitfalls to avoid and what to implement the next time for yourself or even how to fix bad code even faster.
I've never felt as if I was a great programmer. Not to say I'm a bad one either, but I feel confident in my abilities as my experience has taught me so much and my ability to adapt to every situation is what makes me a solid programmer. Learning from other people and their code has helped me. Whether their work was good or bad, there's always something you can take from them and their experience, add it to your memories, knowledge, etc.etc.
Ask other people to read your code! Try and see if you get a fellow coworker or similar to have a code review with you. Having someone else comb through your code and ask you questions about your code will provide new insights and critiques to your style and techniques. Learn from your mistakes and others.
Just to give you a bit of encouragement, I've been a professional programmer for 30 years now, and I still find reading other people's code very difficult. The major reason for this, unfortunately, is that the quality of the code follows Sturgeons Law - 90% of it is crap. So don't think it's your fault if you find it hard going!
The biggest improvement in readability of my code came about when I started liberally using white space.
I found this article on Joel on Software to be very relevant to the Hungarian notation debate.
It seems that the original intent of the notation was to encode type information that wasn't immediately obvious- not whether a variable is an int (iFoo), but what kind of int it is- such as a distance in centimeters (cmFoo). That way, if you see "cmFoo = mBar" you can tell that it's wrong because even though both are ints, one is meters and the other is centimeters, and thus the logic of the statement is incorrect, even though the syntax is fine. (Of course, I personally prefer to use classes such that that statement wouldn't even compile, or would do the conversion for you).
The problem was at some point people started using it without understanding it, and the world was cursed with lots of dwFoos and bBars.
Everyone needs to read that article- Making Wrong Code Look Wrong
How do I increase my code
understanding/reading skills?
Reading code is like dancing by yourself. You need a partner, and I suggest a debugger.
Stepping through code with a debugger is a true, lively dance. I recommend getting a quality, open-source project in the language of your choice, and then step through with the debugger. Concepts will come alive if you ask "why did that happen?", "what should happen next?".
One should ultimately be able to reason about code without a debugger; don't let it become a crutch. But that said, it is a very valuable tool.
Reading code is a lot like reading literature in that you need to have some insight into the author sometimes to understand what you're looking at and what to expect. They only way to improve your comprehension skills is by reading as much code and possible and trying to follow along.
I think a lot of what is mentioned here is applicable to coding...
Reading and understanding skills are a question of time. You will improve them as you get more experienced. Also depends in the quality of the code you are reading.
Keep in mind that sometimes it's not the best idea to learn directly from what you see at work. Books will teach you the best practices and you will be able to adapt them to yourself with the experience.
I am reading the Head First Design Patterns at present and it is very useful. It presents the information in a novel way that is easy to understand. Nice to see they have a C# version for download.
There will always be struggles with reading code unless you are Jon Skeet. This isn't to say that it is a big problem, rather that unless you can eat, sleep, breathe in that programming language, it will always take a little time to digest code. Looking at other people's code is certainly a good suggestion for helping in some ways but remember that there are many different coding conventions out there and some may be more enforced than others, e.g. interface names start with an I to give a simple example. So, I guess I'm saying that even with Visual Studio and Resharper, there is still a little work to understand a few lines of code since I can't quite write out sentences in C# yet.
1) Educate yourself. Read relevant literature.
2) Write code
3) Read code
4) Read relevant blogs.
Visit http://hanselminutes.com . He is a programmer from microsoft. Even though you don't program on microsoft stack, it's good to read through. There is a podcast in there that answers this question.
Another suggestion is to make sure you have the appropriate tools for the job before you start digging into a piece of code. Trying to understand a code-base without the ability to search across the entire set of files is extremely difficult.
Granted, we very rarely have the entire set of files, especially in large projects, but whatever boundaries you draw, you should have good visibility and searchability across those files. Whatever lies outside those boundaries can be considered 'black box' and perhaps lies outside the scope of your grokking.
There are many good open source editors including Eclipse and the CDT. Spending some time learning how to effectively create projects, search across projects, and enable any IDE-specific tooltips/helpers can make a world of difference.
I am a fairly junior programmer and have the task of interviewing an experienced mainframe COBOL programmer for a position doing C++ development for Windows Mobile. By experienced I mean that the candidate's entire programming career has been COBOL.
I am not biased against any particular language, just slightly concerned about my ability to do a thorough interview.
Inside of an interview how can I, with no COBOL experience, get a good feel for the abilities of this interviewee?
Are there any specific things I should ask or look for?
I have already read up on a lot of general interview stuff on SO, what would be helpful are any specific things I look for given the nature of the candidate's background.
The best thing is, give him a task, similar to what he will have to do at your company.
Tell him he can use pseudo code (So no Internet is needed).
Also, The main problem Cobol people have is to grasp OO (Since Cobol is mostly procedural...I am aware of new OO versions).
One more pitfall Cobol people have is grasping the scope concept, As traditional Cobol each variable live from start to bottom of the app he is in.
If this person is a good programmer at all, he/she have had experience with other languages. (Speaking as an old fart who started with COBOL and even worse RPG/II.) Even if this person have never had a job with anything else.
Here are some things you might ask:
"How did you get started with computers?"
"Do you do any programming for fun?"
"Why do you want to move to a C++ environment?" (This is an especially good question because good COBOL programmers are actually hard to find now. I'll bet this person wants to learn something new.)
"Have you done any assembly language programming?" (Odds are much better they'll take to C/C++ quickly if they are comfortable with the machine.)
"Can you describe what 'object oriented programming' means?" (Keys: look for a description of what "objects" are, "inheritance", and "polymorphism". If that works out, ask when they'd use inheritance vs aggregation, ie, "is a" relations vs "has a" relations.)
"Do you have a Windows computer at home or do you have a real computer?"
If they claim any C++ knowledge, a really good set of screening questions are:
"What is the difference between a declaration and a definition in C?"
"What are the differences among 'private', 'protected' and 'public' declarations in a class?"
"What is a 'friend'?" (Extra credit if they know to say that "In C++ only your friends can access your private parts.")
"What is a virtual member function?"
"What is 'virtual inheritance'?"
Make sure they know and understand structs/classes, types, polymorphism, templates, functions, and most importantly pointers.
Make sure they understand the syntax. How would they declare a pointer to a void function that takes two integer arguments, for example? How would they solve the most vexing parse?
How can initialization lists optimize code? Are they familiar with the Standard Template Library?
Can they hand-code a primitive linked list or vector array by hand?
These things are what you want in a programmer capable of writing efficient and clean code.
Isn't it more important to figure out how good the interviewee is in regards to C++, if that's what he is supposed to work on?