Regular Expressions with Conditional Logic in Fluent Forms

Regular expression is not a library nor is it a programming language. Instead, regular expression is a sequence of characters that specifies a search pattern in any given text (string).

Basic Examples of Regular Expressions

Regex	Matches any string
gray\|grey	contains {gray, grey}
gr(a\|e)y	contains {gray, grey}
[Bb]treef\\k	contains {Btreefk, btreefk}
\d{5}(-\d{4})?	contains a United States zip code
1\d{10}	contains an 11-digit string starting with a 1
^cat	begins with “cat”
cat$	ends with “cat”
^cat$	is exactly “cat”
Hello\nworld	contains Hello followed by a newline followed by world
\d	contains {0,1,2,3,4,5,6,7,8,9}
\d+(\.\d\d)?	contains a positive integer or a floating point number with exactly two characters after the decimal point.
[2-9]\|[12]\d\|3[0-6]	contains an integer in the range 2..36 inclusive

Let’s try to add a Regular Expression with Conditional Logic in a Form to understand it better. See the below screenshot –

Create a new or existing form to include the Conditional Logic with Regular Expression.

Add the input fields (For example, Radio Buttons, Checkboxes, Multiple Choices, etc), which will dictate the conditional input fields. For demonstration purposes, we are using the Text Input field here.

Add the Conditional input fields that will respond to specific user actions.

Go to the Input Customization of the conditional input field.

Go to Advanced Options and choose Yes in the Conditional Logic option.

Define the Input fields that the conditional field would rely upon.

Define what logics are to be satisfied- equal/not equal, greater than/less than, contains, start with/ends with/Regex match. Here, we will choose the Regex match.