Thread: C, C++ difference - getting confused

Originally Posted by s5s

1. Is C still gaining popularity or is it being replaced by C++?

That varies over time. C and C++ are both popular languages. New people are taking them up. Some people are transitioning from using other languages to C or C++. Some people are even transitioning from one to the other.

Add other mainstream programming languages into the mix, and the normal ebb and flow of people learning new things, and the popularity of all programming languages changes over time. Sometimes the popularity (as a percentage of people programming) of any specified programming increases, sometimes it decreases. There is no programming language that is used by 100% of the programming community, and very few languages (esoteric or not) with a non-existent programmer base.

I do not consider that C is being replaced by C++, or vice versa. Both have an active developer community, and both are used to address real-world problems. There is a significant number of C developers who won't touch C++, and a significant number of C++ developers who won't touch C. There is a significant number of people who use both, depending on the job at hand. Since a large part of C is technically part of C++, there is some confusion (among more people than will admit to it) due to people believing they are programming in C or C++, when in reality they are programming in some hybrid of the two.

Originally Posted by s5s

I know a lot of projects and code out there is in C simply because a stable C++ compiler was only released about 10-15 years ago whereas a stable C compiler has existed for a while.

That's a really old excuse. In early days of C++, compatibility with C was leveraged to build its usage. Part of the political pushback against that, by C developers who did not want to see their numbers eroded, was to claim that C++ compilers were less mature, less stable, more resource hungry, and things like that.

Part of the early problem with acceptance of C++ was that some of those claims were true, or had significant elements of truth, at the time.

People who are pushing that line today, however, are way out of date. The quality of compiler technologies has improved and matured considerably. Both C and C++ compilers have improved as a result, and the claims are no longer true for either language. Both C and C++ are general purpose languages, and it is possible to list advantages and disadvantages each has over the other, depending on the task at hand. There are also many tasks where C and C++ are equally applicable, and the choice between them comes down to human (developer, management, etc) preferences.

Originally Posted by s5s

2. What is the niche that C is supposed to fill and that C++ is less suited for?

C was originally designed as a system programming language, with the virtue that it could get "close to the machine". C++ was primarily designed around supporting higher levels of abstraction, which means a lot can be done with a relatively small amount of code.

Since then, C and C++ have each evolved. C is still "closer to the machine" than C++ is, and C++ supports more abstraction than C does.

The evolution of C (after the 1989 standard) has introduced more features for getting "close to the machine", but also supports higher levels of abstraction than earlier versions of C did. C++ has evolved mainly in the direction of supporting more abstractions, but the original 1989 C standard is (mostly) still a subset of C++, albeit C++ provides alternatives to a lot of the features that are in C.

There are very few tasks that, objectively, C or C++ are suited where the other is poorly suited. There are trade-offs, but the trade-offs are not as marked as they were in the past. Human preference is what often sways the choice.

Originally Posted by s5s

I know C is a lot simpler that C++ and a simpler thing is easier to use even when you are a master on the subject.

You know wrong.

C is actually quite a complex language and library. It is true that C++ is more complex. However, C is not so simple that it is significantly easier to learn than C++. C is complex enough that it is difficult to learn. The relative ease of learning C or C++ depends on the mindset of the person learning it, rather than their complexity. For some people, the complexity of C is easier to grasp than the complexity of C++. And vice versa. And some people are able to learn both, and use either one, depending on the task at hand.

The "C is simpler than C++" mantra was originally part of the political mantra of some C developers trying to slow down the rate at which some of their colleagues took up C++.

Originally Posted by s5s

3. What is the problem writing OOP code with C? You can code a single class in a single file.

There are a lot of OO design features that C++ is designed to support, and C is not. It is possible to implement any OO design in C, but the amount of code that the programmer need to write to implement that design is usually larger. C++, on the other hand, was designed with OOP in mind, so the C++ compiler takes care of a lot of relevant details that a C programmer would need to account for.

Originally Posted by s5s

4. A lot of people talk about C and C++ as though they are totally different languages.

They are, although the picture is murky as they have a large subset of syntax and library features in common.

All programming languages are associated with particular design techniques, architectural approaches (how a system is conceptually organised), and idioms that programmers leverage to maximise their effectiveness in that language. C and C++ each have their own set of idioms, techniques, and architectural styles that they support better than each other. Irrespective of the fact that a lot of things can be done in the language/library subset that is common to both C and C++, the state of the art in both languages involves using VERY different techniques.

Originally Posted by s5s

I've heard expression such as "Oh you can't use C++ for that, you need to learn C.".

Someone who says that doesn't actually understand either language properly.

It is true that some designs are easier to implement in C or C++, but there is very little that one can do that the other absolutely cannot. The determinate is mindset and effort by the developer.

Originally Posted by s5s

Sure the libraries are different and there are some new keywords in C++ that do things that a library does in C but they are v. v. similar to me.

You're focusing on syntax and libraries. The main areas where C and C++ differ are in architecture (how the program, overall, is structured) and contributing design techniques.

The argument that a C++ compiler is much more difficult to make, I think, is overrated.
Remember: there exists today open source free C++ compilers that anyone can use.
Of course, if you are using it for a new platform, then you need to rewrite parts of the compiler to produce proper assembly code. However, compilers typically tend to be split into front ends and back ends. The front ends compile into some immediate language that the back ends understands. The back ends then take that and make it into assembly code.
The thing here is that the back end need to be rewritten for any given target platform, but the front end generally does not. Because of that, it generally doesn't matter if you are using C or C++, because either way, the back end needs to be rewritten and the front end is already written.
The other problem is the standard library, and there are already good implementations since most of it is already written in standard C++, and the few parts that can usually be implemented by the front end.

Yes, it will probably cost more than a C compiler, but not prohibitively more so.

1. I don't think either C or C++ are gaining in popularity these days. They are stable languages in widespread use, but they aren't gaining territory, mainly because there isn't too much territory to be gained.

2. C doesn't really have a niche separate from C++. They both really target the same niche, but C++ aims to make object-oriented programming much simpler.

3. OOP is certainly possible in C, but manually implementing common OOP features like polymorphism, multiple interfaces/inheritance, etc. using C isn't trivial, and you lose some compile-time type checking that you'd have in C++.

4. They are very similar languages, but they are not the same. Think of them like Norwegian and Swedish - they are mutually intelligible to a large degree, but each has its differences. A lot of the differences are preferred style - while you could compile a well-written C program as C++ and mostly it will work, it's probably not going to look all that much like a well-written C++ program, because each language has its preferred method of doing things, especially in terms of input and string handling. Java and C# are also very similar languages to C and C++, though again each has its own flavor.