What is the best way to get the count/length/size of an iterator?

Question

Is there a \"computationally\" quick way to get the count of an iterator?

int i = 0;
for ( ; some_iterator.hasNext() ; ++i ) some_iterator.next();
         


        

Answer 1

iterator object contains the same number of elements what your collection contained.

List a =...;
Iterator i = a.iterator();
int size = a.size();//Because iterators size is equal to list a's size.

But instead of getting the size of iterator and iterating through index 0 to that size, it is better to iterate through the method next() of the iterator.