Question

I need to define a regex for a string with the following requirements:

• Maximum 20 characters
• Must be in the form Name,Surname
• No numbers and special characters allowed (again, it’s a name&surname)

I already tried something like ^[^1-9\?\*\.\?\$\^\_]{1,20}[,][^1-9\?\*\.\?\$\^\_\-]{1,20}$ but as you can find, it also matches a 40 chars long string.

How can I check for the whole string’s maximum length and at the same time impose 1 comma inside of it and obviously not at the borders?

Thank you

Answer 1

Try the regex:

^(?=[^,]+,[^,]+$)[a-zA-Z,]{1,20}$

Rubular Link

Explanation:

^                : Start anchor
(?=[^,]+,[^,]+$) : Positive lookahead to ensure string has exactly one comma
                   surrounded by at least one non-comma character on both sides.
[a-zA-Z,]{1,20}  : Ensure entire string is of length max 20 and has only
                   letters and comma
$                : End anchor