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Matches exactly 1 numeric digit (0-9).

Matches 5 numeric digits, such as a zip code.

Numeric and hyphen 5+4 ZIP code match for ZIP+4.

This regular expression will match either a 5 digit ZIP code or a ZIP+4 code formatted as 5 digits, a hyphen, and another 4 digits. Other than that, this is just a really really long description of a regular expression that I'm using to test how my front page will look in the case where very long expression descriptions are used.

Matches any single upper- or lower-case letter.

Matches any string of only upper- and lower- case letters (no spaces).

Matches any alphanumeric string (no spaces).

Positive integer value.

Matches any signed integer.

The password's first character must be a letter, it must contain at least 4 characters and no more than 15 characters and no characters other than letters, numbers and the underscore may be used

Simple email expression. Doesn't allow numbers in the domain name and doesn't allow for top level domains that are less than 2 or more than 3 letters (which is fine until they allow more). Doesn't handle multiple "." in the domain ([email protected]).

This regular expressions matches dates of the form XX/XX/YYYY where XX can be 1 or 2 digits long and YYYY is always 4 digits long.

The "hello world" of regular expressions, this will match any string with an instance of 'foo' in it.

This matches a single numeric digit between 1 and 5, and is the same as saying ^[12345]$.

This matches a single numeric digit between 1 and 5, and is the same as saying ^[1-5]$.

This expression matches email addresses, and checks that they are of the proper form. It checks to ensure the top level domain is between 2 and 4 characters long, but does not check the specific domain against a list (especially since there are so many of them now).

This expression matches a hyphen separated US phone number, of the form ANN-NNN-NNNN, where A is between 2 and 9 and N is between 0 and 9.

This expression matches three different formats of postal codes: 5 digit US ZIP code, 5 digit US ZIP code + 4, and 6 digit alphanumeric Canadian Postal Code. The first one must be 5 numeric digits. The ZIP+4 must be 5 numeric digits, a hyphen, and then 4 numeric digits. The Canadian postal code must be of the form ANA NAN where A is any uppercase alphabetic character and N is a numeric digit from 0 to 9.

US Phone Number -- doesn't check to see if first digit is legal (not a 0 or 1).

Yet another simple email validator expression.