C++ vs C

[ResidentBiscuit]

Ok so I'm sure this question has been asked a million times, but what is the practical differences between C++ and C? When would you use one over the other? I understand C is a lower level language and speaks with the hardware much easier and safer, but how? And is there much of a syntax difference between the two?

[ceruleus]

In C++ you can have classes. That's pretty much it.

[hanst99]

I understand C is a lower level language and speaks with the hardware much easier and safer, but how?

Your understanding is wrong. You can program just as low level in C++ as you could in C, just that C++ also has high level language features that C does not have. And "low level access" and "safety" are inversely proportional.

And is there much of a syntax difference between the two?

Not much, most "syntax differences" would be stuff like additional keywords. In general, you could compile most C programs pretty much unchanged with a C++ compiler. (there are certain things that C++ does not support, such as variable length arrays - not sure if they changed that with C++11, I see no reason why they would want to do that though - and the C standard headers have slightly different names to avoid collisions (for example, stdio.h is called cstdio in C++).

When would you use one over the other?

You use C when you want to write a library that's available for both C and C++, for interacting with legacy code and when there's no C++ compiler available. I can't think of any other reasons.

[moorecm]

This is sure to be a thread full of different opinions, but here's mine. The difference is that C++ is better. It has more features (built-in support for more paradigms, etc.) than C and offers more, safer, and more extensible capability in its standard library. You can do anything in C++ that can be done in C (and vice versa).

I'm aware of only 3 valid arguments to use C over C++:

1) In existing codebases it may be easier/faster/cheaper to maintain just C.
2) Existing developers don't know C++, or don't understand how to use it in an effective, scalable way.
3) Platform (usually embedded) doesn't have C++ compiler(s) at all or that are stable enough.

[ceruleus]

Oh! I forgot:

There's this nifty thing called new that basically replaces C's malloc() in C++. Similarly C's free() is replaced by C++'s delete

new and delete FTW!

[ResidentBiscuit]

Well, I have done most of my programming in C++, but I keep hearing that I should also learn C. I am currently a CS major, and would like to have as much knowledge as I can. Should I learn C? Or is it close enough that I can just not spend too much time on C specifically and just port my C++ knowledge over into C?

[BHX]

C++ adds a few features, new reserved words, and of course everything I've read says that any C program can compile with a C++ compiler and all C programs are valid C++ programs. The differences are subtle in my opinion.

[hanst99]

Learning C is imho a waste of time, unless your employer expects you to use C. When starting a new project, I see hardly any point in choosing C over C++ (again, that is only if a C++ compiler is available for that platform. Many microcontrollers for example only have C compilers available for them).

[ResidentBiscuit]

Hmm, well next semester I have the option of taking a course just on C. Not sure if I should or if I should look into something else

[hanst99]

Again - if you already know C++ well, you don't need to learn C. The only "new" thing you'd learn is how to use the C standard library. And you may gain some additional experience in how excessive use of pointers can fuck up your programs.

[Athar]

Hmm, well next semester I have the option of taking a course just on C. Not sure if I should or if I should look into something else

No, don't waste your time. You can start worrying about C when you have to actually work on a C project.
As long as you know what the differences between C and C++ are, you should be able to write C programs if you have to. You just have to keep in mind that memory management has to be done manually, as RAII isn't possible, classes have to be emulated with C structs and free functions, you can't use the STL containers and algorithms, templates have to be emulated with macros where possible, you use error codes instead of exceptions, etc.

[Kyon]

C++ is a superset of an older C standard. Meaning that C++ surely adds new features to C. But since the point where that started, C has been updated a few times too. Comparing them has since then become a bit more complex.