(PHP 5 >= 5.2.0, PHP 7, PHP 8)
This iterator can be used to filter another iterator based on a regular expression.
RegexIterator::ALL_MATCHESReturn all matches for the current entry (see preg_match_all()).
RegexIterator::GET_MATCHReturn the first match for the current entry (see preg_match()).
RegexIterator::MATCHOnly execute match (filter) for the current entry (see preg_match()).
RegexIterator::REPLACEReplace the current entry (see preg_replace(); Not fully implemented yet)
RegexIterator::SPLITReturns the split values for the current entry (see preg_split()).
RegexIterator::USE_KEYSpecial flag: Match the entry key instead of the entry value.
RegexIterator::INVERT_MATCHInverts the return value of RegexIterator::accept().