Iz: http://www.net-comber.com/regxx.html
JavaScript Regular Expression Test Page using RegExp(re,ig)
For nerds, geeks, programmers & coders. By Jim Shook 11/16/2001

Since regexp() adds leading and trailing slashes (//), you don't have to.
Try out these basic 4 first:
\d = Matches any Single Digit [0-9]
\D = Matches any Single Non-Digit Character [^0-9]
\w = Matches any Single Word Character [a-zA-Z0-9]
\W = Matches any Single Non-Word Character [^a-zA-Z0-9]

 Type in a test character string.
Type in a test Regular Expression.
Type in 'i' ignore case, 'g' global, 'ig' for both or nothing (null) for case sensitive nonglobal.



Result or Match String Output.

  Cut & Paste String-In to try out examples ## 01-16:

  String-In =     abc123!@#DEF456$%^

  ##  RegEx   String-Out   (comments)

  01  /\d/    "1"
  02  /\D/    "a"
  03  /\d+/   "123"  (+ gives multiple chars. of first occurence)
  04  /\D+/   "abc"

  05  /\d/g   "1", "2", "3", "4", "5", "6"  (elements of an array)
  06  /\D/g   "a", "b", "c", "!", "@", "#", "D", "E", "F", "$", "%", "^"
  07  /\d+/g  "123", "456"
  08  /\D+/g  "abc", "!@#DEF" "$%^"

  09  /\w/    "a"
  10  /\W/    "!"
  11  /\w+/   "abc123"
  12  /\W+/   "!@#"

  13  /\w/g   "a", "b", "c", "1", "2", "3", "D", "E", "F", "4", "5", "6"
  14  /\W/g   "!", "@", "#", "$", "%", "^"
  15  /\w+/g  "abc123", "DEF456"
  16  /\W+/g  "!@#", "$%^"

Next, try these four:
\s = Matches any Single character of white space
\S = Matches any Single character Non white space
\b = Matches word boundaries
\B = Matches Non-Word boundaries

  Cut & Paste String-In to try out examples ## 17-32:

  String-In =     This is a very short sentence.

  ##  RegEx   String-Out   (comments)

  17  /\s/    " " (white space)
  18  /\S/    "T"
  19  /\s+/   " "
  20  /\S+/   "This"

  21  /\s/g   " ", " ", " ", " ", " " (5 white spaces)
  22  /\S/g   "T", "h", "i", "s", "i", "s", "a", "v", "e", "r", ...
  23  /\s+/g  " ", " ", " ", " ", " "
  24  /\S+/g  "This", "is", "a", "very", "short", "sentence."

  25  /\b/    ""   (null, empty string)
  26  /\B/    ""
  27  /\b+/   null (empty string)
  28  /\B+/   null

  29  /\b/g   "", "", "", "", "", "", "", "", "", "", "", ""
  30  /\B/g   "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", ""
  31  /\b+/g  null
  32  /\B+/g  null

  Have fun!