Regular Expressions 101

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/
^-?(?:[1-9][0-9]*(?:,[0-9]+)?|[1-9][0-9]{1,2}(?:,[0-9]{3})+)$
/
gm
^ asserts position at start of a line
-
matches the character - with index 4510 (2D16 or 558) literally (case sensitive)
Non-capturing group
(?:[1-9][0-9]*(?:,[0-9]+)?|[1-9][0-9]{1,2}(?:,[0-9]{3})+)
1st Alternative
[1-9][0-9]*(?:,[0-9]+)?
Match a single character present in the list below
[1-9]
1-9 matches a single character in the range between 1 (index 49) and 9 (index 57) (case sensitive)
Match a single character present in the list below
[0-9]
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
Non-capturing group
(?:,[0-9]+)?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
, matches the character , with index 4410 (2C16 or 548) literally (case sensitive)
Match a single character present in the list below
[0-9]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
2nd Alternative
[1-9][0-9]{1,2}(?:,[0-9]{3})+
Match a single character present in the list below
[1-9]
1-9 matches a single character in the range between 1 (index 49) and 9 (index 57) (case sensitive)
Match a single character present in the list below
[0-9]
{1,2} matches the previous token between 1 and 2 times, as many times as possible, giving back as needed (greedy)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
Non-capturing group
(?:,[0-9]{3})+
+ matches the previous token between one 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)
Match a single character present in the list below
[0-9]
{3} matches the previous token exactly 3 times
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
$ asserts position at the end of a line
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

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