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

for Java 8 you could use,

public static int getIteratorSize(Iterator iterator){
        AtomicInteger count = new AtomicInteger(0);
        iterator.forEachRemaining(element -> {
            count.incrementAndGet();
        });
        return count.get();
    }