iterator vs. subscript

Question

I have a question about the preference between iterator and subscripting. For example, if I am doing something like:

for (vector<int>::size_type i = 0; i != ivec.size(); ++i) {
  ivec[i] related operation
}

for (vector<int>::iterator it = ivec.begin(); it != ivec.end(); ++it) {
  *it related operation
}

Which one is preferred? In the perspective of: 1. Performance 2. Clarity 3. Other concerns?

I am aware this question have been previously discussed link. But in the other post it only talked about the performance cost of size();

Suppose this is about vector, and the cost of size() is negligible.

what about cost of using subscript vs. iterator?

Thanks.

@AlanShore There are 24 answers there, surely one meets your standards. — Rapptz, Mar 01 '13 at 05:53
Playing devil's advocate, similar questions have been asked [15 times before](http://stackoverflow.com/search?q=%5Bc%2B%2B%5D+iterator+vs+indices). — Rapptz, Mar 01 '13 at 05:56

score 1 · Accepted Answer · answered Mar 01 '13 at 05:51

1

Perfomance: with vector in most cases these cases are equal, since vector<T>::iterator is really pointer to T in most cases.

Clarity: work with iterator.

answered Mar 01 '13 at 05:51

ForEveR

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Even better, C++11: `for ( auto i : ivec )` – us2012 Mar 01 '13 at 05:52
@us2012 even better `for (auto& i : ivec)` or `(const auto& i : ivec)` if we talking about T, not simply `int`. – ForEveR Mar 01 '13 at 05:55

iterator vs. subscript

1 Answers1