I allow only one hyphen (-) in regex

Question

I have a text box where i get the last name of user. How do I allow only one hyphen (-) in a regular expression?

^([a-z A-Z]*-){1}[a-z A-Z]*$

Answer 1

you can use negative lookahead to reject strings having more than one hyphen:

^(?![^-]+-[^-]+-)[a-zA-Z- ]+$

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