How to validate a (country specific) phone number

Question

A valid phone number contains:

• Less than 9 characters
• A "+" at the start
• Only digits.

I\'m trying to use regular expre

Answer 1

Your regex should look like this, you need information about char counter

@"^(\+[0-9]{9})$"

Answer 2

If you're looking for a country specific regex, try this expression which works for all Australian (+61-) numbers. I've put comments on how to go about varying it for other uses.

public static bool IsValidPhoneNumber(string phoneNumber)
{
    //will match +61 or +61- or 0 or nothing followed by a nine digit number
    return Regex.Match(phoneNumber, 
        @"^([\+]?61[-]?|[0])?[1-9][0-9]{8}$").Success;
    //to vary this, replace 61 with an international code of your choice 
    //or remove [\+]?61[-]? if international code isn't needed
    //{8} is the number of digits in the actual phone number less one
}