Regular Expressions

Using

Regular expressions can be added as constraints to text questions. They allow you to specify that the answer must fit a specific pattern such as an email address or a phone number. For example:

regex(. , '^[a-zA-Z]*$')

The first parameter of the above regex function is a ‘dot’. This refers to the current question. So assuming you have added the above as a constraint on a text question then it will ensure that the answer only includes upper and lowecase english type alphabetic characters.

More Examples

regex(. , '^[0-9]*$')                                               -- Numbers Only
regex(. , '^([a-zA-Z0-9._%-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4})*$')    -- An email address

Refer to this website for more examples of regular expressions.

Note

When using examples from the above link do not include the slashes (‘/’) at the beging and end or the regular expression.