Throughout the course of the book, we have seen Regular Expression Extractor post processors in action in several of our scenarios. These components allow you to extract values from a server response using a Perl-type regular expression. As a post processor, this element executes after each sample request in its scope, applying the regular expression; extracts the requested values, generating the template string; and finally stores the result into a given variable name, which can then be referenced further down the test plan. To fully maximize the use of the Regular Expression Extractor post processor, you should get acquainted with regular expressions in general. There are numerous online resources that can help, but you can start with this one: http://www.regular-expressions.info/tutorial.html. The RegExp Tester view is one of the options that you can choose from the View Results Tree listener drop-down menu. It allows you to test various regular expressions...