Regular Expressions 101

Pro

^start of line

Non-Capturing Group(?:\s?$[A-Z],[A-Z]$(?:\s$[A-Z],[A-Z]$)?)*

*repeats the group contents below any number of times:

\s?optionally matches any whitespace character

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

Character Class[A-Z]

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

,the literal , (44₁₀ / 54₈ / 2C₁₆)

Character Class[A-Z]

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

Non-Capturing Group(?:\s$[A-Z],[A-Z]$)?

?repeats the group contents below at most once:

\sany whitespace character

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

Character Class[A-Z]

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

,the literal , (44₁₀ / 54₈ / 2C₁₆)

Character Class[A-Z]

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

$end of line

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.

25 tokens

^(?:\s?\([A-Z],[A-Z]\)(?:\s\([A-Z],[A-Z]\))?)*$

(A,B)
(A,B) (B,C)
(A,B) (B,C) (C,D)
(A,B) (B,C) (C,D)
(A,B) (B,C)

(A,B)
(A,B) (B,C)
(A,B) (B,C) (C,D)
(A,B) (B,C) (C,D)
(A,B) (B,C)