Regular Expressions 101

Pro

^start of line

Negative Lookahead(?!.*([A-Z]{2}).*\1)

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

Group 1([A-Z]{2})

Character Class[A-Z]{2}

{2}matches exactly 2 characters from the set below:

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

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

\1the text saved by group 1

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

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

^(?!.*([A-Z]{2}).*\1).*

New

AL,RA,GD
AL
AL,RA
AL,IS,GD
AL,RA,AL
AL,AL
AL,RA,RA
AL,IS,AL
IS,IS,AL
IS,GD,GD
IS,GD,IS

AL,RA,GD
AL
AL,RA
AL,IS,GD
AL,RA,AL
AL,AL
AL,RA,RA
AL,IS,AL
IS,IS,AL
IS,GD,GD
IS,GD,IS