Regular Expressions 101

^start of line

Group 1((([A-Z]+\d*)(?!.*,\3\b)),)*

*repeats the group contents below any number of times:

Group 2(([A-Z]+\d*)(?!.*,\3\b))

Group 3([A-Z]+\d*)

Character Class[A-Z]+

+matches at least one character from the set below:

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

\d*a digit, repeated any number of times

Negative Lookahead(?!.*,\3\b)

.*any character (except for line terminators), repeated any number of times

,the literal , (44₁₀ / 54₈ / 2C₁₆)

\3the text saved by group 3

\ban ASCII word boundary

,the literal , (44₁₀ / 54₈ / 2C₁₆)

Character Class[A-Z]+

+matches at least one character from the set below:

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

\d*a digit, repeated any number of times

$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.

Search reference

Regular Expression

^((([A-Z]+\d*)(?!.*,\3\b)),)*[A-Z]+\d*$

New

ASAEW1,ASAEW2,ASA,S4,ASAEW5,ASAEW6,ASAEW7
ASAEW1,ASAEW2,ASA,S4,ASAEW5,ASAEW6,ASAEW7,ASAEW6
ASAEW1,ASAEW2,ASA,S4,ASAEW5,ASAEW6,ASAEW7,
ASAEW1,ASAEW2,,ASA,S4,ASAEW5,ASAEW6,ASAEW7

Regular Expression

Substitution