Class

Character matched

.

Any character except newline, [^\n]

[...]

Any one of the characters between the brackets

[^...]

Any one character not one of the characters between the brackets

[\b]

A backspace character (special syntax because of the \b boundary)

\d

Any digit, [0-9]

\D

Any character not a digit, [^0-9]

\s

Any white space character, [ \t\n\r\f\v]

\S

Any non-white space character, [^ \t\n\r\f\v]

\w

Any word character, [a-zA-Z0-9_]

\W

Any non-word character, [^a-zA-Z0-9_]