Regular Expressions 101

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/
(?!\d*[ -]\d)[^\d][+-]?\d*([.,]\d*)?(?<!-)(?!\d*[ -]\d)
/
gi
Negative Lookahead
(?!\d*[ -]\d)
Assert that the Regex below does not match
\d
matches a digit (equivalent to [0-9])
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
Match a single character present in the list below
[ -]
-
matches a single character in the list - (case insensitive)
\d matches a digit (equivalent to [0-9])
Match a single character not present in the list below
[^\d]
\d matches a digit (equivalent to [0-9])
Match a single character present in the list below
[+-]
? 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 insensitive)
\d
matches a digit (equivalent to [0-9])
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
1st Capturing Group
([.,]\d*)?
? 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 a single character in the list ., (case insensitive)
\d
matches a digit (equivalent to [0-9])
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
Negative Lookbehind
(?<!-)
Assert that the Regex below does not match
- matches the character - with index 4510 (2D16 or 558) literally (case insensitive)
Negative Lookahead
(?!\d*[ -]\d)
Assert that the Regex below does not match
\d
matches a digit (equivalent to [0-9])
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
Match a single character present in the list below
[ -]
-
matches a single character in the list - (case insensitive)
\d matches a digit (equivalent to [0-9])
Global pattern flags
g modifier: global. All matches (don't return after first match)
i modifier: insensitive. Case insensitive match (ignores case of [a-zA-Z])
Your regular expression does not match the subject string.Try launching the debugger to find out why.

Regular Expression
No Match

/
/
gi

Test String