Regular Expressions 101

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/
^((https?:)(\/\/\/?)([\w]*(?::[\w]*)?@)?([\d\w\.-]+)(?::(\d+))?)?([\/\\\w\.()-]*)?(?:([?][^#]*)?(#.*)?)*
/
gmi
^ asserts position at start of a line
1st Capturing Group
((https?:)(\/\/\/?)([\w]*(?::[\w]*)?@)?([\d\w\.-]+)(?::(\d+))?)?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
2nd Capturing Group
(https?:)
http
matches the characters http literally (case insensitive)
s
matches the character s with index 11510 (7316 or 1638) literally (case insensitive)
: matches the character : with index 5810 (3A16 or 728) literally (case insensitive)
3rd Capturing Group
(\/\/\/?)
\/ matches the character / with index 4710 (2F16 or 578) literally (case insensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case insensitive)
\/
matches the character / with index 4710 (2F16 or 578) literally (case insensitive)
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
4th Capturing Group
([\w]*(?::[\w]*)?@)?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
Match a single character present in the list below
[\w]
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
\w matches any word character (equivalent to [a-zA-Z0-9_])
Non-capturing group
(?::[\w]*)?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
: matches the character : with index 5810 (3A16 or 728) literally (case insensitive)
Match a single character present in the list below
[\w]
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
\w matches any word character (equivalent to [a-zA-Z0-9_])
@ matches the character @ with index 6410 (4016 or 1008) literally (case insensitive)
5th Capturing Group
([\d\w\.-]+)
Match a single character present in the list below
[\d\w\.-]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
\d matches a digit (equivalent to [0-9])
\w matches any word character (equivalent to [a-zA-Z0-9_])
\. matches the character . with index 4610 (2E16 or 568) literally (case insensitive)
- matches the character - with index 4510 (2D16 or 558) literally (case insensitive)
This hyphen is treated literally, which might be confusing for others. Consider escaping it or placing at the start or end of the class!
Non-capturing group
(?::(\d+))?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
: matches the character : with index 5810 (3A16 or 728) literally (case insensitive)
6th Capturing Group
(\d+)
\d
matches a digit (equivalent to [0-9])
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
7th Capturing Group
([\/\\\w\.()-]*)?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
Match a single character present in the list below
[\/\\\w\.()-]
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
\/ matches the character / with index 4710 (2F16 or 578) literally (case insensitive)
\\ matches the character \ with index 9210 (5C16 or 1348) literally (case insensitive)
\w matches any word character (equivalent to [a-zA-Z0-9_])
\. matches the character . with index 4610 (2E16 or 568) literally (case insensitive)
()
matches a single character in the list () (case insensitive)
- matches the character - with index 4510 (2D16 or 558) literally (case insensitive)
This hyphen is treated literally, which might be confusing for others. Consider escaping it or placing at the start or end of the class!
Non-capturing group
(?:([?][^#]*)?(#.*)?)*
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
8th Capturing Group
([?][^#]*)?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
Match a single character present in the list below
[?]
? matches the character ? with index 6310 (3F16 or 778) literally (case insensitive)
Match a single character not present in the list below
[^#]
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
# matches the character # with index 3510 (2316 or 438) literally (case insensitive)
9th Capturing Group
(#.*)?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
# matches the character # with index 3510 (2316 or 438) literally (case insensitive)
.
matches any character (except for line terminators)
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
Global pattern flags
g modifier: global. All matches (don't return after first match)
m modifier: multi line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)
i modifier: insensitive. Case insensitive match (ignores case of [a-zA-Z])
Your regular expression does not match the subject string.

Regular Expression
No Match

/
/
gmi

Test String