AJAX - The Complete Reference

584 Part IV: Appendixes

However, this comment form is not allowed within actual script and is solely supported as

the first line within a <script> tag. In this manner they are used as a browser workaround

to mask script from nonsupporting user-agents.

Character Meaning

* Match previous item zero or more times

+ Match previous item one time or more

? Match previous item zero or one time

{m, n} Match previous item at minimum m times, but no more than n times

{m, } Match previous item m or more times

{m} Match previous item exactly m times

TABLE A-22 Regular Expression Repetition Quantifiers

Character Meaning

[chars] Any one character indicated either explicitly or as a range between the

brackets

[^chars] Any one character not between the brackets represented explicitly or as a

range

. Any character except newline
\w Any word character; same as [a-zA-Z0-9_]

\W Any nonword character; same as [^a-zA-Z0-9_]

\s Any whitespace character; same as [ \t\n\r\f\v]

\S Any nonwhitespace character; same as [^ \t\n\r\f\v]

\d Any digit; same as [0-9]

\D Any nondigit; same as [^0-9]

\b A word boundary; the empty “space” between a \w and \W

\B A word nonboundary; the empty “space” between word characters

[\b] A backspace character

TABLE A-23 Regular Expression Character Classes