Thread: C++ STL: Why use member iterators

I just started C++ last week (but have been goofing around with other programming languages). I just started looking around the STL (vectors in specific) and why use the iterators? It seems like less typing to just make your own 'for loop' if you are going to step through an array. You can use the size function to check that you don't go out of bounds.

Are iterators quicker because the processor doesn't have to jump around as much or something (me totally guessing)?

It's fine to use array syntax to loop through a vector.

There are more advanced things you can do with iterators, and they are a more generic concept. If you have a function (like sort for example) that works on a container, then you can have it take iterators so that it works with any container that supports that kind of iteration.

Also, in some cases you may want to use the iterator version to loop through a vector because it can be easier to update the code if you switch to a different container type later.

Also, keep in mind that some containers only support iterators, such as std::list.

Originally Posted by Daved

It's fine to use array syntax to loop through a vector.

There are more advanced things you can do with iterators, and they are a more generic concept. If you have a function (like sort for example) that works on a container, then you can have it take iterators so that it works with any container that supports that kind of iteration.

Also, in some cases you may want to use the iterator version to loop through a vector because it can be easier to update the code if you switch to a different container type later.

Also, you can pass an iterator to a function and it can use it. Try doing that with just an index...

Thank you for answering. I went ahead and played around with them last night. Orignally it just looked like extra typing. Thanks!