Hi I need a regular expression which is accepting the following strings:
[A-Z]-[A-Z]{3-5}[0-9]{2-4}
for example X-ABC123 or Y-AB1234
The problem now is that the total length of the string on the right side of the hyphen must always be 5 chars in length. Is there a chance to check that with regular expressions only?
Just add this after the hyphen :
/(?=[A-Z\d]{5}$)/
Resulting in :
/^[A-Z]-(?=[A-Z\d]{5}$)[A-Z]{3,5}[0-9]{2,4}/
This assumes that your input strings are the strings you posted.
X-ABC123 -> fails
Y-AB1234 -> fails
A-ABD12 -> matches
A-ABV111 -> fails
If the string is part of another string you can replace the $ anchor with \s|$ for example.
(?=[A-Z\d]{0,5}$) instead of (?=[A-Z\d]{5,5}$)?
$ anchor by \b a word boundary
{0,5} when just {5} is correct: must always be 5 chars in length (not up to 5){5} is enough, {5,5} is not needed
First the problems in your regex
The quantifier is {3,5} and not {3-5} (this would match literally "{3-5}")
You want 3 to 5 letters and 2 to 4 digits and in total 5 letters and digits ==> the only valid combination is then 3 letters followed by 2 digits.
In general you can use a positive lookahead for this
^[A-Z]-(?=.{5}$)[A-Z]{3,5}[0-9]{2,4}$
See it here on Regexr
The (?=.{5}$) part is just looking, if there are from its position to the end ($) 5 characters.
But as said before, if the 3-5 and 2-4 and overall 5 is valid you can just do
^[A-Z]-[A-Z]{3}[0-9]{2}$
. for a length check. The wanted characters are then matched by the following pattern.
I think it's definitely possible, from a language theory point of view. Just group it and add the constraint :
I just need to know which language is specifying the regex but something like this :
[A-Z]-(^[A-Z][A-Z0-9]4)
I had the feeling you wanted the right part to start with one char for sure, then either chars or numbers
