Combine two regular expression into one while validating Attribute

Question

I have two regular expression.

1. [RegularExpression(@".*[^ ].*", ErrorMessage ="Something")] validate string that only contains spaces(Not any other characters Ex: " ".length = 7).
2. [RegularExpression(@"^[^~!@#$%&*]+$", ErrorMessage = "something")] validate string that contains ~!@#$%&* special characters.

How can I combine both regex into one, because Duplicate Regular expression annotation is not allowed in asp.net mvc.

Answer 1

You may use

^[^~!@#$%&*]*[^~!@#$%&*\s][^~!@#$%&*]*$

See the regex demo

Details

• ^ - start of string
• [^~!@#$%&*]* - 0+ chars other than a char in the ~!@#$%&* list
• [^~!@#$%&*\s] - a char other than a char in the ~!@#$%&* list and whitespace
• [^~!@#$%&*]* - 0+ chars other than a char in the ~!@#$%&* list
• $ - end of string.

NOTE: To also allow an empty string you need to wrap the pattern between the anchors within an optional group: ^(?:[^~!@#$%&*]*[^~!@#$%&*\s][^~!@#$%&*]*)?$.