Regular Expressions 101

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/
<i class="fa[sb] fa-([\w\-]*)"(><\/i>|\s?\/>)
/
gm
<i class="fa
matches the characters <i class="fa literally (case sensitive)
Match a single character present in the list below
[sb]
sb
matches a single character in the list sb (case sensitive)
fa-
matches the characters fa- literally (case sensitive)
1st Capturing Group
([\w\-]*)
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 4510 (2D16 or 558) literally (case sensitive)
" matches the character " with index 3410 (2216 or 428) literally (case sensitive)
2nd Capturing Group
(><\/i>|\s?\/>)
1st Alternative
><\/i>
><
matches the characters >< literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
i>
matches the characters i> literally (case sensitive)
2nd Alternative
\s?\/>
\s
matches any whitespace character (equivalent to [\r\n\t\f\v ])
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
> matches the character > with index 6210 (3E16 or 768) literally (case sensitive)
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)
Your regular expression does not match the subject string.Try launching the debugger to find out why.

Regular Expression
No Match

/
/
gm

Test String