Requirement is : Field is made of alpha characters and numbers, we not allow same character repeated more than 3 times continuously
Regex: ^([0-9A-Z])(?!\\1+$)[0-9A-Z]$
the above reg ex validate and not allow if the same charater repeated but we need to validate only more than 3 times repeated consinutly
ex: 1AAA23 -- Allowed
2AAAA34 -- Not Allowed as 'A' repeated more tha 3 times
22A22B5 -- Allowed
A222256 -- Not allowed as '2' repeated more than 3 times
VN00000 -- Not allowed
111123 -- Not allowed
1111AA -- Not allowed
111AAA -- Allowed
The pattern that you tried only match 2 characters in total, and those characters can not be the same.
You can write the pattern like:
^(?!.*([A-Z0-9])\1{3})[A-Z0-9]+$
^ Start of string(?! Negative lookahead, assert that to the right is not
.*([A-Z0-9])\1{3} Optionally match any char and then capture 1 or chars A-Z0-9 in group 1 followed by matching that same char 3 times) Close lookahead[A-Z0-9]+ Match 1+ repetitions of chars A-Z0-9$ End of string