Introducing Regular Expressions: JavaScript and TypeScript

Appendix

As a quick reference, here you will find all the metacharacters and their descriptions.

Table A-1. Characters

Abbreviation	Description
.	Any character
[]	One out of an inventory of characters
[ˆ]	One not in the inventory of characters
.	The dot
\	Masking special chars
\\	The backslash

Table A-2. Groups

Abbreviation	Description
()	Counting group.
(?:)	Non-counting groups.
(?=)	Lookahead reference. Matches if the next character matches.
(?=!)	Negative lookahead reference. Matches if the next character does not match.

Table A-3. Operators

Operator	Meaning	Description
?	0 – 1	Zero or one character(s)
*	0 – ∞	Zero or any number of characters
+	1 – ∞	One or any number of characters
{zahl}	number	Exact “number” of characters
{min,}	min – ∞	Minimum ...