Advantages of using arrays instead of std::vector?

Question

I'm currently seeing a lot of questions which are tagged C++ and are about handling arrays.
There even are questions which ask about methods/features for arrays which a std::vector would provide without any magic.

So I'm wondering why so much developers are chosing arrays over std::vector in C++?

Answer 1

In general, I strongly prefer using a vector over an array for non-trivial work; however, there are some advantages of arrays.

• arrays are slightly more compact: the size is implicit
• arrays are non-resizable; sometimes this is desireable
• arrays don't require parsing extra STL headers (compile time)
• it can be easier to interact with straight-C code with an array (e.g. if C is allocating and C++ is using)

Answer 2

Because C++03 has no vector literals. Using arrays can sometime produce more succinct code.

Compared to array initialization:

char arr[4] = {'A', 'B', 'C', 'D'};

vector initialization can look somewhat verbose

std::vector<char> v;
v.push_back('A');
v.push_back('B');
...

Answer 3

I'd go for std::array available in C++0x instead of plain arrays which can also be initialized like standard arrays with an initializer list

http://www2.research.att.com/~bs/C++0xFAQ.html#std-array

Answer 4

I think this is because a lot of C++ programmers come from C and don't yet understand the advantages of using vector and all the extra STL goodies that come for free with its containers.