Regular Expressions 101

^start of line

Group group(?<group> (?<value>[^()\r\n]+)* $(?<groupVal>(?&group)|(?&value))$ (?&groupVal)* )

Group value(?<value>[^()\r\n]+)*

*repeats the group contents below any number of times:

Negated Character Class[^()\r\n]+

+matches at least one character outside the set below:

(the literal ( (40₁₀ / 50₈ / 28₁₆)

)the literal ) (41₁₀ / 51₈ / 29₁₆)

\ra carriage return (ASCII 13)

\na line-feed (newline) character (ASCII 10)

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

Group groupVal(?<groupVal>(?&group)|(?&value))

1st Alternative(?&group)

(?&group)calls group group as a subroutine

2nd Alternative(?&value)

(?&value)calls group value as a subroutine

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

(?&groupVal)*calls group groupVal as a subroutine, repeated any number of times

$end of line

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

x modifier: extended. Ignores unescaped whitespace and comments outside character classes

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^(?<group>
  (?<value>[^()\r\n]+)*
  \((?<groupVal>(?&group)|(?&value))\)
  (?&groupVal)*
)$

New

(F(i(r(s)t))) ((S)(e)((c)(o))n)d) (((((((Third)))))))
(F(i(r(s)t))) ((S)(e)((c)(o))n)d (((((((Third)))))))
((F(i(r(s)t))) ((S)(e)((c)(o))n)d) (((((((Third)))))))

Regular Expression

Substitution