The Regex Coach is an excellent software program to learn regular expressions as it displays realtime results in its interface. The interface itself is divided into two display panes that contain the regular expression and the target strings. Below are tabs and buttons that provide additional functionality.

A user who wants to test a regular expression would enter it in the first column and add a target string in the second. The program automatically highlights the area of the target string that is matched by the regular expression. Any modification to the regular expression will automatically be visualized in the target string pane.

Invalid entries are displayed automatically as a status message. The program will for instance notify the user if a bracket has not been closed which would make the expression invalid.

The Regex Coach is a learning by doing aid for learning or verifying regular expressions. There is still need for a documentation on regular expressions like this one.