%% Return Substrings Using match Keyword
% Capture words within a character vector that contain the letter x.

str = 'EXTRA! The regexp function helps you relax.';
expression = '\w*x\w*';
matchStr = regexp(str,expression,'match')

% The regular expression '\w*x\w*' specifies that the character vector:
% Begins with any number of alphanumeric or underscore characters, \w*.
% Contains the lowercase letter x.
% Ends with any number of alphanumeric or underscore characters after the x, including none, as indicated by \w*.
% Copyright 2012 The MathWorks, Inc.