Hi,
I noticed a few snippets recently where a size_t variable was used for array indices, and after searching around I'm still not sure what the obvious advantage of using a size_t variable over a typical int would be..

To clarify, what would be the difference between this:

for(size_t i=0;i<5;i++)
//do something with arr[i]

..and this:

for(int i=0;i<5;i++)
//do something else with arr[i]

Is it worth using size_t variables in fairly generic, simple console apps etc or do it's advantages (if any) only become apparent at a much higher level of complexity..?

Not urgent, was just interested :)

portability :

"The actual type of size_t is platform-dependent; a common mistake is
to assume size_t is the same as unsigned int, which can lead to
programming errors, particularly as 64-bit architectures become more
prevalent"

Comments
..just what I was looking for.

Some c++ stl classes, such as string, vector, and list, return size_t in some of its methods. For example. std::vector size() returns size_t value. Some compilers (such as Microsoft) will produce warnings if you attempt to compare size_t with int or long.

Thanks for the responses.
So then the main advantage is portability..
Does that mean that size_t variables will literally be different sizes on 32-bit and 64-bit systems? And is it common practise to use them for array indices?

OK, guess I'll start using them regularly then. Thanks for all the replies.

This question has already been answered. Start a new discussion instead.