Regular Expressions 101

1st Alternative^(?=\d{1,2}([wp])(?:\d{1,2}(?!\1)[wp]\d{1,2}\1)*(?:\d{1,2}(?!\1)[wp])?$)\d{1,2}[wp]

^start of line

Positive Lookahead(?=\d{1,2}([wp])(?:\d{1,2}(?!\1)[wp]\d{1,2}\1)*(?:\d{1,2}(?!\1)[wp])?$)

\d{1,2}a digit, repeated between 1 and 2 times

Group 1([wp])

Character Class[wp]

wthe literal w (119₁₀ / 167₈ / 77₁₆) (case sensitive)

pthe literal p (112₁₀ / 160₈ / 70₁₆) (case sensitive)

Non-Capturing Group(?:\d{1,2}(?!\1)[wp]\d{1,2}\1)*

*repeats the group contents below any number of times:

\d{1,2}a digit, repeated between 1 and 2 times

Negative Lookahead(?!\1)

\1the text saved by group 1

Character Class[wp]

wthe literal w (119₁₀ / 167₈ / 77₁₆) (case sensitive)

pthe literal p (112₁₀ / 160₈ / 70₁₆) (case sensitive)

\d{1,2}a digit, repeated between 1 and 2 times

\1the text saved by group 1

Non-Capturing Group(?:\d{1,2}(?!\1)[wp])?

?repeats the group contents below at most once:

\d{1,2}a digit, repeated between 1 and 2 times

Negative Lookahead(?!\1)

\1the text saved by group 1

Character Class[wp]

wthe literal w (119₁₀ / 167₈ / 77₁₆) (case sensitive)

pthe literal p (112₁₀ / 160₈ / 70₁₆) (case sensitive)

$end of line

\d{1,2}a digit, repeated between 1 and 2 times

Character Class[wp]

wthe literal w (119₁₀ / 167₈ / 77₁₆) (case sensitive)

pthe literal p (112₁₀ / 160₈ / 70₁₆) (case sensitive)

2nd Alternative(?!^)\G\d{1,2}[wp]

Negative Lookahead(?!^)

^start of line

\Gstart of current search

\d{1,2}a digit, repeated between 1 and 2 times

Character Class[wp]

wthe literal w (119₁₀ / 167₈ / 77₁₆) (case sensitive)

pthe literal p (112₁₀ / 160₈ / 70₁₆) (case sensitive)

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

^(?=\d{1,2}([wp])(?:\d{1,2}(?!\1)[wp]\d{1,2}\1)*(?:\d{1,2}(?!\1)[wp])?$)\d{1,2}[wp]|(?!^)\G\d{1,2}[wp]

New

2w
1p
3w1p3w
2p12w2p3w
2p12p2w3p
2p121w2p3w