Regular Expressions 101

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/
[^".”()\d]?(\.{1}\s?)[^".”()\s].
/
g
Match a single character not present in the list below
[^".”()\d]
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
".”()
matches a single character in the list ".”() (case sensitive)
\d matches a digit (equivalent to [0-9])
1st Capturing Group
(\.{1}\s?)
\.
matches the character . with index 4610 (2E16 or 568) literally (case sensitive)
{1} matches the previous token exactly one time (meaningless quantifier)
\s
matches any whitespace character (equivalent to [\r\n\t\f\v \u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000\ufeff])
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
Match a single character not present in the list below
[^".”()\s]
".”()
matches a single character in the list ".”() (case sensitive)
\s matches any whitespace character (equivalent to [\r\n\t\f\v \u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000\ufeff])
. matches any character (except for line terminators)
Global pattern flags
g modifier: global. All matches (don't return after first match)
Your regular expression does not match the subject string.

Regular Expression
No Match

/
/
g

Test String