Regular Expression Playground

Help

The Regular Expression Playground is old. There are much better tools now. If you are looking for a tool to test regular expressions, I recommend regular expressions 101.

Result:

"Welcome to the Regular Expression Playground! Edit 'Text' and 'Regular
Expression' ('pattern,' 'm/pattern/flags,' or 's/from/to/flags'). Matches
or substitutions are highlighted within the 'Result' text. Uncheck 'Show
matches/substitutions' to quiz yourself. Matched groups (parentheticals)
are displayed along the right side." -Burkeware

Show matches/substitutions

Regular Expression:

Modifiers
Ignore case (i)
Global (g)
Multi-line (m)

Text:

Groups

Match 0		Regular Expression Playground
	Group 1	d
Match 1		-Burkeware
	Group 1	are

Hints

. matches any character
\d, \w, and \s match digit, word character, and whitespace
\D, \W, and \S (negate) match non-digt, non-word character, and non-whitespace
+ one or more times
* zero or more times (greedy)
*? zero or more times (lazy)
? zero or one time
^ matches beginning of line
$ matches end of line
{n,m} n to m times (inclusive), {n} exactly n times
[0-9] or [ABCdef] matches one character in set
[^0-9]+ leading circumflex (^) negates, so matches one or more non-digits
| match either pattern to left or pattern to right
() to define groups (referenced as $1, $2, ...)
\ for literal next character — e.g., \? for literal question mark and \\ for backslash (\)

References