Ruby - Regular Expressions Special Characters and Symbols

Introduction

The Special Characters and Symbols Within Regular Expressions are listed in the following table.

Character	Meaning
^	Anchor for the beginning of a line
$	Anchor for the end of a line
\A	Anchor for the start of a string
\Z	Anchor for the end of a string
.	Any character
\w	Any letter, digit, or underscore
\W	Anything that \w doesn't match
\d	Any digit
\D	Anything that \d doesn't match (non-digits)
\s	Whitespace (spaces, tabs, newlines, and so on)
\S	Non-whitespace (any visible character)

To match only letters and digits:

"This is a test".scan(/\w\w/) { |x| puts x }