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

java iterator
Zak picture Zak · Mar 15, 2012 · Viewed 170.1k times · Source

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

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

... seems like a waste of CPU cycles.

Answer

Andrejs picture Andrejs · Nov 11, 2014

Using Guava library:

int size = Iterators.size(iterator);

Internally it just iterates over all elements so its just for convenience.

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