Ignore Pattern Whitespace); Validates the format, type, and length of the supplied input field.The input must consist of 3 numeric characters followed by a dash, then 2 numeric characters followed by a dash, and then 4 numeric characters. This content is outdated and is no longer being maintained.To validate a server control's input using a Regular Expression Validator The regular expression used in the preceding code example constrains an input name field to alphabetic characters (lowercase and uppercase), space characters, the single quotation mark (or apostrophe) for names such as O'Dell, and the period or dot character.
It is provided as a courtesy for individuals who are still using these technologies. They can get ridiculously convoluted as in the case above and, according to the specification, are often too strict anyway. If you actually check the Google query I linked above, people have been writing (or trying to write) RFC-compliant regular expressions to parse email addresses for years.Enclosing the expression in the caret (^) and dollar sign ($)markers ensures that the expression consists of the desired content and nothing else.A ^ matches the position at the beginning of the input string and a $ matches the position at the end of the input string.