RegEx号码未被其他号码包围

Question

I'm trying to get a six digit number that is not surrounded by any other number, and is not in a sequence of numbers. This number can exist at the beginning of the string, anywhere in it, and at the end. It can also have commas and text in front of it, but most importantly distinct 6 digit blocks of numbers. I've pulled my hair out doing lookaheads and conditions and can't find a complete solution that solves all issues.

Sample data:

00019123211231731ORDER NO 761616 BR ADDRESS 123 A ST
ORDER NO. 760641 JOHN DOE
REF: ORDER #761625
OP212312165 ORDER NUMBER 759699 /REC/YR 123 A ST
766911
761223,761224,761225

Answer 1

(^|\D)(\d{6})(\D|$). You will find your needed 6 digit match in capturing group 2. Notice that this solution is reliable only for one match. It won't find both numbers in 123456,567890 (Thank you Alan for pointing this out!). If multiple matches are needed a lookaround solution should be used.

With look-arounds:

(?<=^|\D)\d{6}(?=\D|$)

or with look-arounds and the condition to be a valid number (i.e. the first digit is not 0):

(?<=^|\D)[1-9]\d{5}(?=\D|$)