Regular Expressions 101

Group 1(\d+)

\d+a digit, repeated at least once

\s*any whitespace character, repeated any number of times

Positive Lookahead(?=((?!\)).)*\(|[^()]*$)

1st Alternative((?!\)).)*\(

Group 2((?!\)).)*

*repeats the group contents below any number of times:

Negative Lookahead(?!\))

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

.any character (except for line terminators)

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

2nd Alternative[^()]*$

Negated Character Class[^()]*

*matches any number of characters outside the set below:

(the literal ( (40₁₀ / 50₈ / 28₁₆)

)the literal ) (41₁₀ / 51₈ / 29₁₆)

$end of string, or before its final line terminator

Global pattern flags

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

Detailed match information will be displayed here automatically.

25 tokens

Regular Expression

(\d+)\s*(?=((?!\)).)*\(|[^()]*$)

New

1Hello2Hai (in 2:3) 3hi 4 bye

\n$1