Ruby Regular Expressions Cheat Sheet

[abc]

A single character of: a, b, or c

[^abc]

Any single character except: a, b, or c

[a-z]

Any single character in the range a-z

[a-zA-Z]

Any single character in the range a-z or A-Z

^

Start of line

$

End of line

\A

Start of string

\z

End of string

.

Any single character

\s

Any whitespace character

\S

Any non-whitespace character

\d

Any digit

\D

Any non-digit

\w

Any word character (letter, number, underscore)

\W

Any non-word character

\b

Any word boundary

(...)

Capture everything enclosed

(?<n>...)

Named-capture of everything enclosed, named n

(?:...)

Non-capture group

(a\|b)

a or b

a?

Zero or one of a

a*

Zero or more of a

a*?

Zero or more of a, lazily (shortest possible)

a+

One or more of a

a+?

One or more of a, lazily

a{3}

Exactly 3 of a

a{3,}

3 or more of a

a{3,}?

3 or more of a, lazily

a{3,6}

Between 3 and 6 of a