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Closed 10 years ago.
C++ has too many features, and I can't see how any programmer is able to remember all these features while programming. (We can see how this affected the design of newer languages, such as Java)
So, what I need is a list of features that are enough to know, disregarding all the others, to create c++ programs, perhaps created by someone who thought the same way as I did.
Hope I was clear enough.
Learn Resource Acquisition Is Initialization.
The technique was invented by Bjarne Stroustrup, to deal with resource deallocation in C++.
[...]
RAII is vital in writing exception-safe C++ code: to release resources before permitting exceptions to propagate (in order to avoid resource leaks) one can write appropriate destructors once rather than dispersing and duplicating cleanup logic between exception handling blocks that may or may not be executed.
C++ is an object-oriented language with features like inheritance, encapsulation and polymorphism that is also found in popular languages like Java, C# etc. C++ also features generics via templates. However, in C++ you have to explicitely handle memory deallocation (ie. no garbage collection). This makes it very important to be able to release resources and deallocate memory in a controlled manner, and that is why I believe RAII is a very fundamental concept in C++. You will have a hard time understanding a "smart pointer" unless you understand RAII.
This is really an impossible to create list. Every place I work has a different acceptable subset of C++. So its going to be different depending on what you're developing on. I've seen C++ that truly is just C with occasional use of the "class keyword" to very run-time polymorphism oriented code to template meta-programming heavy code. Then the practices are going to change based on what frameworks/libraries/platforms you are targeting.
The best I could suggest is reading various coding standards and seeing the how they suggest you ought to write code using C++.
Google's Coding Standard
Sutter's Coding Standard Book
You learn and remember them by having a need for them. I'm not sure what sort of "features" you're looking for. "virtual functions" are definitely something you want to learn, but I don't really know your background. Should I be suggesting polymorphism/class inheritance too? Template classes/functions?
I think templates are such a feature...
Do you have a tool box containing too many tools? Then don't use them all? Use the ones you need.
Read a good book with C++ best practices and design patterns.
Don't be in too much of a rush to master a language. Peter Norvig (of Google) argues that it takes about 10 years to gain a mastery at anything.
Related
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Closed 10 years ago.
I've been programming C++ and Java for quite a while now and have some questions about common C++ architecure.
When I program in Java I try to mimic the standard library, that is using interfaces such as Iterable and Serializable and having similar naming conventions and functionality. With C++ however, I hesitate when trying to mimic the STL conventions (with the exception of iterators).
I've boiled it down to the following questions (are the following common convention to implement):
Allocators
Interfaces (classes with only pure virtual methods)
Templates instead of abstract base classes
Restricting exception throwing...
... or having a class optionally throw exceptions (such as in std streams)
Using typedefs for, more or less, obvious types (reference_type, pointer_type, value_type, ...)
Or is the std of C++ not worth mimicing at all?
Thank you for your opinions / answeres!
The more I've used C++, the less fond I am of mimicking the best of libraries I find. The problem comes in when we get a junior developer on the team. They'll understand the basics, but not the subtleties of the language. They may know how to create a map or list using the template syntax, but be unable to understand it when it's applied to another object. The added complexities of debugging and doing code read-throughs also take valuable time away from solving problems or advancing your product.
I have grown to lean towards using the most basic features of the language, which typically leaves the code in a more naturally readable state. I've regretted deviations from this path when I go back 8-12 months later to hunt down an obscure bug with the code.
Java, on the other hand, has more simplistic library implementations that is very well understood by more junior Java developers. I do find that junior Java developers tend to have a greater understanding of the language then junior C++ developers. The being said, C++ developers have more opportunity to become truly competent owing to the lower level of thought needed to become an intermediate C++ programmer.
It greatly depends on your project. The general advice seems to be: Don't bother having a concrete standard for C++.
E.g. with typedefs there are multiple opinions both "for" and "against".
The reason why a concrete coding style for C++ is less important in C++ is because the language does not provide the ways to enforce and check those styles.
I.e. the grammar isn't easily parsable and therefore there are pretty much no tools to meaningfully style-check / refactor C++ code.
Which means that the weight of the style-check falls on the programmer's shoulders. I.e. it makes less sense to enfore style guides, because then much of the time saved by them is wasted in manual style checks.
So just use whatever your project / company uses or decides to use.
Here are my personal preferences:
Allocators: No opinion. If you need a custom allocator, chances are you'll know better than me what to do with it.
Interfaces: If you're doing any performance-sensitive work - don't. They make things noticeably slower in a realtime application. Both abstract virtual classes and the pImpl pattern.
Templates instead of abstract base classes: It depends. But the general opinion seems to be that templates should be used for container-like functionality and a few other simple cases. Otherwise, it's a decent pattern. Debugging these is still a serious pain and will be in the next few years.
Restricting exception throwing: Yeah, do that. Try not to use exceptions, because believe it or not, in 2012 they are still not universally supported.
Using typedefs:: Just try to use c++11's std::auto. Otherwise, they kind of make your life harder because they're halfway to #define macros. I'd personally use an IDE (or Vim) to ease the typing stress of longs names and write the long names.
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Closed 11 years ago.
I am new to Stack Overflow, and new to programming.
I am learning how to program in C++.
My question is not related to specific code, but is about research and learning the language.
What I have learned so far relates to narrow examples of syntax and simple programs which use variables, functions, arrays, etc.
I am wondering if people have or can link to example programs so I can study them.
I'm looking for console programs which:
use variables (int, double, string, etc)
use functions
use arrays use classes with
attributes and methods use objects of that class
reads and writes to a file
validates user inputs, displaying appropriate error messages
and is basically a useful program.
Through Google, I have mostly only been able to find C++ tutorial pages (cplusplus, cprogramming, etc) which deal with each of the above separately, usually in a bare-bones way to show the syntax. I'm looking for something more complex (but not overly so) so I can learn how to combine these things in a meaningful way with the intent of eventually writing programs of my own at the same level.
I've already coded a calculator (though not one that has all of these features; namely it was missing file i/o and I was able to make a basic one which didn't need objects), so I'm looking for something different. I understand console programs are text based and lend themselves well to these kind of programs, so it can be a calculator of another type, as long as it isn't a basic arithmetic one.
People here won't teach you C++. In fact, even a book or Google by themselves won't exactly teach you any language, they are just tools to make your life easier and the studying curve smoother.
My suggestion is to use Google or a good C++ book and write code.. especially write code, otherwise you won't learn anything, you must get your hands dirty in order to learn C++.
cplusplus.com has a few examples.
As #GMan said, you'd be better off reading a book.
Possibly Effective C++ by Scott Meyers, or maybe one in the Beginner\Introductory section.
The best way to improve is to give yourself a task and code it. Use different techniques/paradigms (OOP, modular, etc). Instead of studying programs, try to create them yourself - you'll learn a lot better this way.
The book can guide you, but you must make the journey.
Here are some exercises. You can try solving puzzles, too. CodeGolf.SE is good if you want to have some fun.
I hope you've got an excellent book. :)
That said, I understand the desire to find source code you can read that's larger than toys, but not giant cathedrals of code; perhaps the AppArmor policy parser can be of service to you. It's a little bit involved, because it's a small-language compiler that builds a DFA of a security policy for 'execution' in the kernel when confined programs perform file operations.
You can clone it with bzr: http://bazaar.launchpad.net/~apparmor-dev/apparmor/master/ or you can browse the source code: http://bazaar.launchpad.net/~apparmor-dev/apparmor/master/files/head:/parser/libapparmor_re/
Supplementing the other posts directing you to various reading, if you are new to programming, I highly recommend starting your venture into programming with Python.
Python is an easy-to-learn programming language that has a LOT built-in and will allow you to start making useful "programs" very quickly.
For example, you can read the entire contents of a text file with a single line of code:
file_contents = open('example.txt','r').read()
I feel it keeps people more encouraged when they can see significant results as they learn. If you are interested, Dive Into Python is a very popular tutorial.
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Closed 12 years ago.
I'm starting C++ programming in my first job. I'm a CS student and I have learn programming in Java. What advice would you tell me to watch out so I don't cause trouble in my new job?
Would you have any advice or references would be appreciated.
(example: I know C++ is more likely to have memory problem than Java)
Thank you very much!
Maybe you already know this, but one common mistake for folks used to Java and learning C++:
Don't use new unless you have to (and you probably don't really have to). In most cases where you want to create an object, you should just create it "on the stack", like ClassType obj;.
Two things:
Get yourself a copy of Effective C++ by Scott Meyers.
Lint your code. This will not only catch potential bugs early in the development process, but also teach you good coding habits (e.g. declaring a method's input arguments as const references). I use PC-Lint for this.
For me, the biggest difference between Java and C++ is pointers, so I would try to get pointers down. Just my opinion.
No two ways about it. You're going to be a menace until you've been bit enough by C++ gotchas to hate the language. I'd recommend trying to write functions and not classes. A lot of people think OOP is great, but really most users want your code to "do" something, not "be" something. Anyways, good luck. :-)
Definitely what Chance said. Memory management is explicit in C++. I had an excellent textbook in college called Deitel C++. It's a C++ Bible.
I would also learn up on the Standard Template Library and Boost.
This might give you some ideas.
Some important excerpts :
Researchers (Bloom (1985), Bryan & Harter (1899), Hayes (1989), Simmon & Chase (1973)) have shown it takes about ten years to develop expertise in any of a wide variety of areas, including chess playing, music composition, telegraph operation, painting, piano playing, swimming, tennis, and research in neuropsychology and topology. The key is deliberative practice: not just doing it again and again, but challenging yourself with a task that is just beyond your current ability, trying it, analyzing your performance while and after doing it, and correcting any mistakes. Then repeat. And repeat again.
And here is how to do :
Get interested in programming, and do some because it is fun. Make
sure that it keeps being enough fun so that you will be willing to
put in your ten years/10,000 hours.
Program. The best kind of learning is learning by doing. To put it
more technically, "the maximal level of performance for individuals
in a given domain is not attained automatically as a function of
extended experience, but the level of performance can be increased
even by highly experienced individuals as a result of deliberate
efforts to improve." (p. 366) and "the most effective learning
requires a well-defined task with an appropriate difficulty level for
the particular individual, informative feedback, and opportunities
for repetition and corrections of errors." (p. 20-21) The book
Cognition in Practice: Mind, Mathematics, and Culture in Everyday
Life is an interesting reference for this viewpoint.
Talk with other programmers; read other programs. This is more
important than any book or training course.
If you want, put in four years at a college (or more at a graduate
school). This will give you access to some jobs that require
credentials, and it will give you a deeper understanding of the
field, but if you don't enjoy school, you can (with some dedication)
get similar experience on your own or on the job. In any case, book
learning alone won't be enough. "Computer science education cannot
make anybody an expert programmer any more than studying brushes and
pigment can make somebody an expert painter" says Eric Raymond,
author of The New Hacker's Dictionary. One of the best programmers I
ever hired had only a High School degree; he's produced a lot of
great software, has his own news group, and made enough in stock
options to buy his own nightclub.
Work on projects with other programmers. Be the best programmer on
some projects; be the worst on some others. When you're the best, you
get to test your abilities to lead a project, and to inspire others
with your vision. When you're the worst, you learn what the masters
do, and you learn what they don't like to do (because they make you
do it for them).
Work on projects after other programmers. Understand a program
written by someone else. See what it takes to understand and fix it
when the original programmers are not around. Think about how to
design your programs to make it easier for those who will maintain
them after you.
Learn at least a half dozen programming languages. Include one
language that supports class abstractions (like Java or C++), one
that supports functional abstraction (like Lisp or ML), one that
supports syntactic abstraction (like Lisp), one that supports
declarative specifications (like Prolog or C++ templates), one that
supports coroutines (like Icon or Scheme), and one that supports
parallelism (like Sisal).
Remember that there is a "computer" in "computer science". Know how
long it takes your computer to execute an instruction, fetch a word
from memory (with and without a cache miss), read consecutive words
from disk, and seek to a new location on disk. (Answers here.)
Get involved in a language standardization effort. It could be the
ANSI C++ committee, or it could be deciding if your local coding
style will have 2 or 4 space indentation levels. Either way, you
learn about what other people like in a language, how deeply they
feel so, and perhaps even a little about why they feel so.
Have the good sense to get off the language standardization effort as
quickly as possible.
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Closed 12 years ago.
What does C++ add to C?
What features of the language are the Clang/LLVM projects, the parts of GCC that are being written in C++, chromium, and any others all taking advantage of? What features are they avoiding?
Like all sophisticated and powerful things there is a price to be paid to succeed in C++.
You have to be incredibly careful with memory management.
Multi-paradigm capability means you have to be really good at design to avoid making a mess.
Extreme performance requires careful planning and selection of features used.
The ability to circumvent most every language policy requires monumental self discipline.
So if you're sloppy with memory, poor at design, don't need fast programs, or have no self discipline, then please don't learn C++. There is always Java or C#.
meta programming? templates?
like with C you get performance, but the code looks horrible.
with the high level languages you get nice code but there is less flexibility to make the fastest possible code.
with c++ you can do both? you can freely make anything as fast as it could be made in C, but native object orientation, and templates/operator overloading ect makes it so you can write fairly nice looking code too. indeed, you can make it so it is neat and fast.
I have never really found it more of a pain to write stuff in c++ than in a higher level language. the trick is having good libraries.
Because despite academic efforts such as Singularity, there's not a single mainstream OS where drivers can be written in a high-level language.
Note that anything that can be done in C++ can also be done in C, but some things are a lot easier in C++.
Not? I would say it's not worth if you performance is not an issue for you. (Follow the double negatives.)
My two cents:
Although I don't program in Python, I would have to say that Python is probably the best programming language for getting real work done. It's an elegant language, and it has an enormous collection of libraries for doing various things. However, my experience as a user has shown me over and over again that Python is slow (take yum, for example).
I do know Haskell pretty well, and I have to say that it's a friggin' awesome language. Better yet, it is compiled, and its speed is competitive with Java and C++ (though you have to put forth extra effort to get this speed in some cases). However, libraries for things like database access don't always match the elegance of Haskell's base libraries (I'm probably way wrong about this), and they're harder to install on Ubuntu. In my opinion, that's why it's more challenging to get real work done in Haskell than in Python.
Ruby's good for web applications. Other than that, it's slow (though I speculate jRuby or something might be faster).
C++ is far from elegant, and in many cases, elegance is frowned apon. Anyone ever told you to use static_cast instead of C-style casting? Anyone ever told you not to use namespace std;? C++ has a lot of features, but doesn't tend to have many important language features (such as closures, which are formally proven to be the best thing since sliced bread).
Why do people use C++, then? Well, it's performance-focused, making it a good choice when you need speed. It has classes, namespaces, and templates, so it's a good choice when you want better code organization, but still need to use "C" for some reason. Also, it has the Boost library, which I've heard is really good for getting work done.
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I'm something of a new, reluctant convert to C++ from a Pascal, Ruby, and PHP background. I haven't worked with Pascal since a few months of torture with "Delphi Turbo;" since then I've practically been eating and sleeping Ruby and PHP. I'm already well acquainted with object oriented programming and many various subjects.
My main trouble is that I already know the rudiments of C/C++ programming, less the actual experience of working with C++. I worked with C for long enough to realize that even without macros, etc, I didn't want to work with it. (Some of the disgust was from maintaining a CGI application in C, when accustomed to Pascal's automatic string management.) I know just enough C++ to be dangerous to myself and anyone else unwitting enough to use my "code."
I'd really like to work up to a good enough understanding of C++ to use libraries like Crypto++ and Boost without major problems or in-depth knowledge of the language's intricacies. I just need to figure out how to work with C++ without killing myself (either with C++, or with the long-standing dislike that I'm already battling).
What are effective resources that will teach me C++ without assuming that I must be retaught all basic programming? I'd rather not relearn concepts that I already know, unless the paradigm in C++ is significantly different. I'm also learning on my own time, so don't recommend me a book complex enough to need a guru to explain to me, please! And I have an effective budget of $0 for learning C++, so please keep suggestions to quality online resources or books common enough that I could likely find them at the library.
Read Effective C++ by Scott Meyers - it's a good guide for getting past the basics of C++ and showing how to write and use "correct" C++ code
The C++ FAQ Lite is a great resource.
I highly recommend Stroustrup: The C++ Programming Language (Third Edition). As the author of C++ he is the authority on the language, and the book is useful as a reference as much as it is for learning the language. It's common enough that most good general purpose libraries will have a copy. He goes into quite some depth on all the features of C++, including explanations of why certain design decisions were made in the language. Personally, I think this is the best book around for programmers to learn C++.
Once you have a good grip on core C++, David Abrahams and Aleksey Gurtovoy's book, C++ Template Metaprogramming, goes into further depth and provides many examples of how C++'s template system allows you to perform complex compile-time programming, a highly valuable skill these days. This one is a little less common but you can probably find it at a university library.
I can give you a couple of keywords you might want to research in more detail:
RAII (Is pretty much the technique that ensures you don't have to worry about memory leaks. Very convenient)
Generic Programming (The STL in particular. Experiment with iterators and the standard library algorithms, and see just how powerful these abstractions are. They're a key part of what I like about C++)
Functors (Perhaps too simple on their own, but the way they can be used instead of function pointers with the algorithms mentioned above is interesting)
And just get familiar with templates, and "mild" forms of template metaprogramming. (Traits classes, for example, and (partial) specializations.
And just keep an eye on the C++ questions here on SO. A lot of interesting topics are regularly brought up.
But the best advice is probably to keep it completely separate from C. Forget everything you learned about how to use C. It either doesn't apply in C++, or leads to inferior code that is harder to read and maintain.
It's an interesting language in its own right, and has a number of unique features. Leverage those, and it can actually be fun to work with C++. Treat it as an overengineered Java, PHP or C, and it'll just make you want to throw up.
You need to write code. A lot of code in C++. There is no substitute. You also need to read good code.
I agree with the suggestion for Scott Meyers' books though. Those are pretty good.
Part of your learning will be the leap from procedural programming to OO.
I would highly recommend the book "C++ Common Knowledge" by Stephen C. Dewhurst. Don't know if it's common enough to be found at the library (it's not at mine, but my library sucks for computer books that aren't 5-10 years out of date), but it does an excellent job of taking the complex aspects of C++ and making them easy to understand, without dumbing anything down for beginners. Definitely worth the investment.
To quote from the back of the book:
This book is for you if
You're no "dummy," and you need to get quickly up to speed in intermediate to advanced C++
You've had some experience in C++ programming, but reading intermediate and advanced C++ books is slow-going
You've had an introductory C++ course, but you've found that you still can't follow your colleagues when they're describing their C++ designs and code
You're an experienced C or Java programmer, but you don't yet have the experience to develop nuanced C++ code and designs
You're a C++ expert, and you're looking for an alternative to answering the same questions from your less-experienced colleagues over and over again
C++ Common Knowledge covers essential
but commonly misunderstood topics in
C++ programming and design while
filtering out needless complexity in
the discussion of each topic. What
remains is a clear distillation of the
essentials required for production C++
programming, presented in the author's
trademark incisive, engaging style.
Here is a link to a question with answers that should help you.
https://stackoverflow.com/questions/1227764/i-need-to-improve-my-c-skills-fast-is-this-realistically-possible/1227805#1227805
For effective stuff you can find online Cplusplus.com has a pretty good reference and information.
If you can find the book "C++ Common Knowledge" (Stephen Dewhurst) at the library or cheaply online, I would add that to the list posted on the StackOverflow link above as well as "The C++ Programming Language" (Stroustrup). Going through the questions under the C++ tag right here on SO should give you some good pointers and code examples to get you on your way.
Here's a list of good C++ books which teach you C++ rather than basics of programming.
Sit down and write some C++ code.