Regular Expressions 101

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

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

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)

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

Group group(?<group>(?&value)*$(?&groupVal)$(?&groupVal)*)

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

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

(?&groupVal)calls group groupVal as a subroutine

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

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

^start of line

(?&group)calls group group as a subroutine

$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

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

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)))))))