I've searched through multiple answers on SO now, but most of them consider the beginning of the line as the whole string being looked upon, which doesn't serve my case, I think (at least all the answers I tried didn't work).
So, I want to match all codes within a text that are 7-digit long, start with 1 or 2, and are not prefixed by "TC-" and its lowercase variants.
Came up with the /(!?TC-){0}(1|2)\d{6}/g expression, but it doesn't work for not matching the codes that start with "TC-", and I don't know how can I prevent from selecting those. Is there a way to do that?
I've created an example pattern on Regexr: regexr.com/6p70c.
CodePudding user response：
You can assert not TC- to the left using negative lookbehind (?<! and omit the {0} quantifier as that makes it optional:
(?<!\bTC-)\b[12]\d{6}\b