Regular Expressions 101

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/
"([^"]*)"|(?<=,|^)([^,]*)(?=,|$)
/
g
1st Alternative
"([^"]*)"
" matches the character " with index 3410 (2216 or 428) literally (case sensitive)
1st Capturing Group
([^"]*)
Match a single character not present in the list below
[^"]
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
" matches the character " with index 3410 (2216 or 428) literally (case sensitive)
" matches the character " with index 3410 (2216 or 428) literally (case sensitive)
2nd Alternative
(?<=,|^)([^,]*)(?=,|$)
Positive Lookbehind
(?<=,|^)
Assert that the Regex below matches
1st Alternative
,
, matches the character , with index 4410 (2C16 or 548) literally (case sensitive)
2nd Alternative
^
^ asserts position at start of the string
2nd Capturing Group
([^,]*)
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 4410 (2C16 or 548) literally (case sensitive)
Positive Lookahead
(?=,|$)
Assert that the Regex below matches
1st Alternative
,
, matches the character , with index 4410 (2C16 or 548) literally (case sensitive)
2nd Alternative
$
$ asserts position at the end of the string, or before the line terminator right at the end of the string (if any)
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