Regular Expressions 101

Pro

Atomic Group(?>(?<=class=")|(?!^)\G)

1st Alternative(?<=class=")

Positive Lookbehind(?<=class=")

class="the literal text class=" (case sensitive)

2nd Alternative(?!^)\G

Negative Lookahead(?!^)

^start of string

\Gstart of current search

Atomic Group(?>\b([-\w]++)\b(?=[^"]*?\s\1[\s"])\s+|[-\w]+\s+\K)

1st Alternative\b([-\w]++)\b(?=[^"]*?\s\1[\s"])\s+

\ban ASCII word boundary

Group 1([-\w]++)

Character Class[-\w]++

++matches at least one character from the set below:

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\wany word character

\ban ASCII word boundary

Positive Lookahead(?=[^"]*?\s\1[\s"])

Negated Character Class[^"]*?

*?matches any number of characters outside the set below:

"the literal " (34₁₀ / 42₈ / 22₁₆)

\sany whitespace character

\1the text saved by group 1

Character Class[\s"]

\sany whitespace character

"the literal " (34₁₀ / 42₈ / 22₁₆)

\s+any whitespace character, repeated at least once

2nd Alternative[-\w]+\s+\K

Character Class[-\w]+

+matches at least one character from the set below:

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\wany word character

\s+any whitespace character, repeated at least once

\Kresets the starting point of the reported match. Any previously consumed characters are no longer included in the final match

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Detailed match information will be displayed here automatically.

25 tokens

(?>(?<=class=")|(?!^)\G)(?>\b([-\w]++)\b(?=[^"]*?\s\1[\s"])\s+|[-\w]+\s+\K)

New

<li class="a-b a-c 3 2 1 is it this or this is it or it is this 1 2 3 a-c a-b">

<li class="a-b a-c 3 2 1 is it this or this is it or it is this 1 2 3 a-c a-b">