Regular Expressions 101

Positive Lookbehind(?<=https://www.facebook.com/groups/)

https://wwwthe literal text https://www (case sensitive)

.any Unicode character (except for line terminators)

facebookthe literal text facebook (case sensitive)

.any Unicode character (except for line terminators)

com/groups/the literal text com/groups/ (case sensitive)

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

Positive Lookahead(?=/)

/the literal / (47₁₀ / 57₈ / 2F₁₆)

Global pattern flags

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

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

(?<=https://www.facebook.com/groups/).*?(?=/)

New

a href="https://www.facebook.com/groups/366139636814727/871873746241311/?comment_id=871905166238169&ref=notif&notif_t=group_comment" class="_33e" data-reactid=".3.0.0.0.0.0.$100000241272846=21446664199525942.0.0"><div class="clearfix" data-reactid=".3.0.0.0.0.0.$100000241272846=21446664199525942.0.0.0"><d

Regular Expression

Substitution