Regular Expressions 101

Positive Lookahead(?=($\d+?$[a-z]$\d+?$|[a-z]$\d+?$|$\d+?$[a-z]))

Group 1($\d+?$[a-z]$\d+?$|[a-z]$\d+?$|$\d+?$[a-z])

1st Alternative$\d+?$[a-z]$\d+?$

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

\d+?a digit, repeated at least once

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

Character Class[a-z]

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

\d+?a digit, repeated at least once

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

2nd Alternative[a-z]$\d+?$

Character Class[a-z]

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

\d+?a digit, repeated at least once

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

3rd Alternative$\d+?$[a-z]

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

\d+?a digit, repeated at least once

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

Character Class[a-z]

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

Global pattern flags

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

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

(?=(\(\d+?\)[a-z]\(\d+?\)|[a-z]\(\d+?\)|\(\d+?\)[a-z]))

New

a(1)a(2)a(1)a