offsetExists($index) examines the cache, not the inner or outer iterator. <?php $cache = new \CachingIterator( new \ArrayIterator(['a', 'b', 'c', 'd']),

Returns true if an entry referenced by the offset exists, false otherwise.

Returns TRUE if an entry referenced by the offset exists, FALSE otherwise. CachingIterator::next · CachingIterator::offsetGet · CachingIterator · PHP Manual.

CachingIterator::__construct — Construct a new CachingIterator object for the iterator ; CachingIterator::count — The number of elements in the iterator ...

Returns TRUE if an entry referenced by the offset exists, FALSE otherwise. CachingIterator::next · CachingIterator::offsetGet · CachingIterator · PHP Manual.

Returns TRUE if an entry referenced by the offset exists, FALSE otherwise.

CachingIterator::__construct — Construct a new CachingIterator object for the iterator. CachingIterator::count — The number of elements in the iterator ...

Returns TRUE if an entry referenced by the offset exists, FALSE otherwise. This function is currently not documented; only its argument list is available.

CachingIterator::__construct — Construct a new CachingIterator object for the iterator · CachingIterator::count — The number of elements in the iterator ...

Returns TRUE if an entry referenced by the offset exists, FALSE otherwise. CachingIterator::next · CachingIterator::offsetGet · CachingIterator · PHP Manual.