What are the often misunderstood concepts in C++? [closed]

Answer 1

C++ is not C with classes!

And there is no language called C/C++. Everything goes downhill from there.

Answer 2

Free functions are not bad just because they are not within a class C++ is not an OOP language alone, but builds upon a whole stack of techniques.

I've heard it many times when people say free functions (those in namespaces and global namespace) are a "relict of C times" and should be avoided. Quite the opposite is true. Free functions allow to decouple functions from specific classes and allow reuse of functionality. It's also recommended to use free functions instead of member functions if the function don't need access to implementation details - because this will eliminate cascading changes when one changes the implementation of a class among other advantages.

This is also reflected in the language: The range-based for loop in C++0x (next C++ version released very soon) will be based on free function calls. It will get begin / end iterators by calling the free functions begin and end.

Answer 3

Arrays are not pointers

They are different. So &array is not a pointer to a pointer, but a pointer to an array. This is the most misunderstood concept in both C and C++ in my opinion. You gotta have a visit to all those SO answers that tell to pass 2-d arrays as type** !

Answer 4

I think the most misunderstood concept about C++ is why it exists and what its purpose is. Its often under fire from above (Java, C# etc.) and from below (C). C++ has the ability to operate close to the machine to deal with computational complexity and abstraction mechanisms to manage domain complexity.

Answer 5

I still don't get why vector doesn't have a pop_front and the fact that I can't sort(list.begin(), list.end())..

Answer 6

Here is an important concept in C++ that is often forgotten:

C++ should not be simply used like an object oriented language such as Java or C#. Inspire yourself from the STL and write generic code.