Regular Expressions 101

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/
(?:http:\/\/?|https:\/\/?)(www\.example\.com\/.*?)"
/
g
Non-capturing group
(?:http:\/\/?|https:\/\/?)
1st Alternative
http:\/\/?
http:
matches the characters http: literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
\/
matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
2nd Alternative
https:\/\/?
https:
matches the characters https: literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
\/
matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
1st Capturing Group
(www\.example\.com\/.*?)
www
matches the characters www literally (case sensitive)
\. matches the character . with index 4610 (2E16 or 568) literally (case sensitive)
example
matches the characters example literally (case sensitive)
\. matches the character . with index 4610 (2E16 or 568) literally (case sensitive)
com
matches the characters com literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
.
matches any character (except for line terminators)
*? matches the previous token between zero and unlimited times, as few times as possible, expanding as needed (lazy)
" matches the character " with index 3410 (2216 or 428) literally (case sensitive)
Global pattern flags
g modifier: global. All matches (don't return after first match)
Your regular expression does not match the subject string.Try launching the debugger to find out why.

Regular Expression
No Match

/
/
g

Test String