Using regular expressions to filter directories with RegexIterator

- In the previous video, GlobIterator wasn't able…to select both JPEG's and PNG files in a single operation.…Moreover, we were limited to a single directory.…Using a regular expression with RegexIterator,…gives you more flexibility.…This is regex.php, which you can find…in the Chapter Three folder of the exercise files.…It contains an instance of RecursiveDirectoryIterator,…which is chained with RecursiveIteratorIterator.…And the path that's passed as the value…to RecursiveDirectoryIterator is a single dot,…which means it'll start at the current directory.…

Since I've copied this file…to the top level of my testing site,…the foreach loop would list every file in the site.…To filter the results, we need to create an instance…of RegexIterator and chain it.…So let's add a new line on line four.…We'll keep the same name for the Iterator:…"files," and it'll be "new," "RegexIterator."…And the first argument is the Iterator…that we want to filter, which is "files."…The second argument needs to be a…Perl Compatible Regular Expression.…