Regular expression notation(正则表达式）

 

Regular expression notation     by Danny Goodman   <JavaScript & DHTML Cookbook>

Character   Matches                 Example
\b     Word boundary               /\bto/                 matches "tomorrow"
                                               /to\b/                 matches "Soweto"
                                               /\bto\b/               matches "to"
\B     Word nonboundary        /\Bto/                    matches "stool" and "Soweto"
                                               /to\B/                    matches "stool" and "tomorrow"
                                                  /\Bto\B/                matches "stool"
\d          Numeral 0 through 9         /\d\d/                       mathces "42"
\D          Nonnumeral                          /\D\D/                         mathes "to"
\s          Single whitespace                 /under\sdog/             matches "under dog"
\S          Single nowwhitespace                  /under\Sdog/         matches "under-dog"
\w          Letter,numeral,or underscore             /1\w/                           matches "1A"
\W          Not a letter,numeral,or undersore     /1\W/                   matches "1%"
.           Any character except a newline        /../                            matches "Z3"
[...]      any one of the character set in brackets        /J[aeiou]y/          matches "Joy"
[^...]      Negated characted set                    /J[^eiou]y/                   matches "Jay"
*           Zero or more times                          /\d*/                   matches "","5", or"444"
?           Zero or one time                              /\d?/                  matches "" or "5"
+           One or more times                          /\d+/               matches "5" or "444"
{n}         Exactly n times                                  /\d{2}/          matches "55"
{n,}        n or more times                                /\d{2,}/          matches "555"
{n,m}       at least n, at most m times             /\d{2,4}/      matches "5555"
^           at beginning of a string or line         /^Sally/        matches "Sally says..."
$           at end of a string or line                    /Sally.$/         matches "hi,Sally."