Field Input Validation Using Regex

What is regex?

Regex (short for regular expression) is a tool used to define patterns within text.

It’s like a flexible search filter that can find, match, or validate specific sequences of characters such as email addresses, phone numbers, postcodes, or dates.

How to use regex in your form

The Short Answer field (under Advanced Settings) includes a variety of input validation options. However, if these don’t meet your specific needs, the Custom Regex option lets you define your own validation rules using a regex pattern.

Example:
Let’s say you want to ensure form users enter a Medicare card expiry date in the format YYYY-MM.

A regex pattern for that would look like this:

^\d{4}-\d{2}$

Here’s how that breaks down:

^ = start of the string
\d{4} = exactly 4 digits (the year)
- = a dash
\d{2} = exactly 2 digits (the month)
$ = end of the string

Tip: If you need help creating a regex pattern for your specific use case, please contact our Support team.

You can also specify a validation error message that will display below the field when the input does not match the regex pattern. This ensures form users receive clear feedback on what needs to be corrected before they can submit the form.

Tip: Use the Custom Regex Test Field to test your regex pattern.

Commonly used regex patterns