array vs vector vs list

Question

I am maintaining a fixed-length table of 10 entries. Each item is a structure of like 4 fields. There will be insert, update and delete operations, specified by numeric posi

Answer 1

Prefer an std::vector over and array. Some advantages of vector are:

• They allocate memory from the free space when increasing in size.
• They are NOT a pointer in disguise.
• They can increase/decrease in size run-time.
• They can do range checking using at().
• A vector knows its size, so you don't have to count elements.

The most compelling reason to use a vector is that it frees you from explicit memory management, and it does not leak memory. A vector keeps track of the memory it uses to store its elements. When a vector needs more memory for elements, it allocates more; when a vector goes out of scope, it frees that memory. Therefore, the user need not be concerned with the allocation and deallocation of memory for vector elements.

Answer 2

First a couple of notes:

A good rule of thumb about selecting data structures: Generally, if you examined all the possibilities and determined that an array is your best choice, start over. You did something very wrong.

STL lists don't support operator[], and if they did the reason that it would be slower than indexing an array has nothing to do with the overhead of a function call.

Those things being said, vector is the clear winner here. The call to operator[] is essentially negligible since the contents of a vector are guaranteed to be contiguous in memory. It supports insert() and erase() operations which you would essntially have to write yourself if you used an array. Basically it boils down to the fact that a vector is essentially an upgraded array which already supports all the operations you need.