I have the following regular expression:
^[a-zA-Z0-9]+( [a-zA-Z0-9]+)*$
I'm trying to validate a string between 0-10 characters, the string cannot contain more the two spaces in a row or cannot be empty. The string cannot contain any special characters and can be case insensitive and can include hyphens.
How can I limit input to between 0-10 characters?
I tried
^[a-zA-Z0-9]+( [a-zA-Z0-9]+{0,10})*$
but it does not work.
I would do it like this:
^(?!.* )(?=.*[\w-])[\w -]{1,10}$
This uses a negative look-ahead (?!.* ) to assert there are not two consecutive spaces, and a positive look-ahead (?=.*[\w-]) to assert it has at least one non-space character (I assume "empty" means "only spaces").
Note that if it can't be "empty", it can't be zero length, so the length range must be 1-10, not 0-10.
Of tiny note is the fact that you don't need to escape the dash in a character class if it's the first or last character.
\w allow for latin\accented characters too?\w includes all "letters", "digits" and the underscore character. "Letters" means any unicode "letter" (includes accents, greek, arabic, the works). "Digits" includes arabic, chinese "numbers" too.^(?i)(?!.* )(?=.*[a-z0-9-])[\wa-z0-9 -]{1,10}$(?i)([a-z?0-9?\-?]\s?){0,10}
Case insensitive, between 0-10 length, matches any combination of letters, numbers, hyphens and single spaces.
(?i)\w([a-z?0-9?\-?]\s?){0,10} added \w to account for accented characters é as i believe these are allowed
test testI think no "+" when using range.
^[a-zA-Z0-9]+( [a-zA-Z0-9]{0,10})*$
Also, you say you accept hyphens, but don't see that here?
So
^[a-zA-Z0-9]+( [a-zA-Z0-9\-]{0,10})*$
AAA AAA. The input cannot contain more than two spaces in a row
if (str.Length > 10)?.lengthproperty provided by the .NET framework. I'd recommend you use multiple regular expressions to perform smaller, much less complex tasks.