Regex

Regex regex = new Regex(@" ^ # anchor at the start (?=.*\d) # must contain at least one numeric character (?=.*[a-z]) # must contain one lowercase character (?=.*[A-Z]) # must contain one uppercase character .{8,10} # From 8 to 10 characters in length \s # allows a space $ # anchor at the end", RegexOptions.IgnorePatternWhitespace);