Regular Expressions 101

Pro

^start of line

Non-Capturing Group(?:[A-Z]{2}(?:,\b)?)+

+repeats the group contents below at least once:

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)

Non-Capturing Group(?:,\b)?

?repeats the group contents below at most once:

,the literal , (44₁₀ / 54₈ / 2C₁₆)

\ban ASCII word boundary

$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

^(?:[A-Z]{2}(?:,\b)?)+$

New

What is allowed:

AL,RA,GD
AL
AL,RA
AL,IS,GD
What it shouldn't be allowed:

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

What is allowed:

AL,RA,GD
AL
AL,RA
AL,IS,GD
What it shouldn't be allowed:

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