Regular expression to check special character

[sri_3464 0]

I need to check whether password has at least 6 characters with at least 1 letter and one special character. I am checking the condition !Regex.IsMatch(strPassword,"(?!^[0-9]*$)(?!^[a-zA-Z]*$)^([a-zA-Z0-9]{6,24})$"). But it doesnot allow special character. I need to change the expression to check if there is at least one special character. Please help me out.

[Mizard X]

^(?=.*[a-zA-Z])(?=.*[0-9])(?=.*[^a-zA-Z0-9]).{6,}$

1. ^ checks for the start of the input string.
2. (?=.*[a-zA-Z]) checks that there are at least one letter.
3. (?=.*[0-9]) checks that there are at least one digit.
4. (?=.*[^a-zA-Z0-9]) checks that there are at least one special character (not a letter nor digit).
5. .{6,} checks that there are at least 6 characters.
6. $ checks for the end if the input string.

See also

• XKCD: Password Strength

-- MizardX (so)