I have this regex ^[A-ZÆØÅa-zæøå\ \-]{2,50}$ for validating names. How can I make it allow only one "-". I want it to accept names like this:
Janet Smith-Johnson
Mary-Ann Johnson
Sara Mary John-Smith
Sara Johnson
Sara Mary Johnson
But it can't allow names that starts with - and ends with -. Like:
-Janet Mary
Mary-
CodePudding user response：
You can use
^(?=.{2,50}$)(?!(?:.*-){2})[A-ZÆØÅa-zæøå] (?:[- ][A-ZÆØÅa-zæøå] )*$
See the regex demo.
If you are using the regex in C# or with u flag in JavaScript that supports ECMAScript 2018 standard, you can also match any Unicode letter with \p{L}:
^(?=.{2,50}$)(?!(?:.*-){2})\p{L} (?:[- ]\p{L} )*$
Details:
^- start of string(?=.{2,50}$)- two to fifty chars in the string allowed(?!(?:.*-){2})(or(?!(?:[^-]*-){2})in the real code is more efficient) - no two hyphens are allowed[A-ZÆØÅa-zæøå]- one or more letters from the set (\p{L}matches any Unicode letter)(?:[- ][A-ZÆØÅa-zæøå] )*- zero or more sequences of either space or-and then one or more letters$- end of string.
CodePudding user response：
You can match your character class without spaces, then optionally repeat a space and again use the character class without spaces.
Then optionally match - and the same mechanism again.
^(?=.{2,50}$)[A-ZÆØÅa-zæøå] (?: [A-ZÆØÅa-zæøå] )*(?:-[A-ZÆØÅa-zæøå] (?: [A-ZÆØÅa-zæøå] )*)?$
The pattern in parts matches:
^Start of string(?=.{2,50}$)Assert 2 - 50 characters[A-ZÆØÅa-zæøå]Match what is listed in the character class without a space(?: [A-ZÆØÅa-zæøå] )*Optionally repeat the character class preceded by a space(?:Non capture group to match as a whole-[A-ZÆØÅa-zæøå]Match what is listed in the character class without a space(?: [A-ZÆØÅa-zæøå] )*Optionally repeat the character class preceded by a space
)?Close the non capture group and make it optional$End of string