Regular Expressions 101

Pro

^start of line

Group 1((?:xxx|yyy)(,(?:xxx|yyy))*)

Non-Capturing Group(?:xxx|yyy)

1st Alternativexxx

xxxthe literal text xxx (case sensitive)

2nd Alternativeyyy

yyythe literal text yyy (case sensitive)

Group 2(,(?:xxx|yyy))*

*repeats the group contents below any number of times:

,the literal , (44₁₀ / 54₈ / 2C₁₆)

Non-Capturing Group(?:xxx|yyy)

1st Alternativexxx

xxxthe literal text xxx (case sensitive)

2nd Alternativeyyy

yyythe literal text yyy (case sensitive)

$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

^((?:xxx|yyy)(,(?:xxx|yyy))*)$

New

xxx
yyy
xxx,xxx
yyy,xxx
xxx,yyy,yyy,yyy
But these would be invalid:

xx
yyyy
xxx,
xxxyyy
xxx,,yyy
,xxx,yyy