Craig Francis

Features

My notes on a single page, based on the information at php.net.

	Escape sequences
\d	any decimal digit
\D	any character that is not a decimal digit
\h	any horizontal whitespace character
\H	any character that is not a horizontal whitespace character
\s	any whitespace character
\S	any character that is not a whitespace character
\v	any vertical whitespace character
\V	any character that is not a vertical whitespace character
\w	any "word" character
\W	any "non-word" character

\b	word boundary
\B	not a word boundary
\A	start of subject (independent of multiline mode)
\Z	end of subject or newline at end (independent of multiline mode)
\z	end of subject (independent of multiline mode)
\G	first matching position in subject

	Explication
(?:red\|white)	Non-capturing sub pattern
(sens\|respons)e and \1ibility	Back reference
foo(?=bar)	Positive lookahead assertion
foo(?!bar)	Negative lookahead assertion
(?<=foo)bar	Positive lookbehind assertion
(?<!foo)bar	Negative lookbehind assertion
(?(condition)yes-pattern)	Conditional subpattern
(?(condition)yes-pattern\|no-pattern)	Conditional subpattern