Conditional Logic is great new feature introduced in Sitecore 9.1 Forms. Basically you can add conditions to show/hide fields based on user input.

In this example below I set up a drop down and couple of sections that show/hide the section(you can go fields as well) based on user interaction.

My simple conditional logic form

Now I added the conditions to drop-down list by clicking on the Conditions section in the form elements pane.

Edit conditions to add new condition logic

Now are you wondering why the condition logic looks weird? Here is how it works –

All Condition are evaluated and applied in sequence.

Foreach condition, if the Condition matches, then apply selected action. Else, apply inverse of selected action.

Added the form to a web page and here is how my output looks –

When I chose 1, showed the Attendee #1 section

When I chose 2, showed both Attendees section

1. Dropdown Selection: Empty

Condition 1 Evaluation = False. Inverse selected action (Hide section1 and section2)

Condition 2 Evaluation = True. Apply selected action (Hide section1)

Results: Hide both section1 and section2

2. Dropdown Selection: 1

Condition 1 Evaluation = False. Inverse selected action (Hide section1 and section2)

Condition 2 Evaluation = False. Inverse selected action (Show section1)

Results: Show section1 and hide section2

3. Dropdown Selection: 2

Condition 1 Evaluation = True. Apply selected action (Show section1 and section2)

Condition 2 Evaluation = False. Inverse selected action (Show section1)

Results: Show both section1 and section2

Now you have the cool working conditional logic on the form. Any questions, please leave a comment.

Happy sitecoring!