This article explains how to use a formula in a Change value action in a form rule.
Use the Change value action to change the value of a field. You can use a formula to update values in a form rule action. Using a formula gives you more control, and you can update values dynamically. That is, create a form rule that uses a single action for multiple factors with a formula, instead of creating an action for each scenario.
For example, in a Tasks app you have a field for the status change log. That is, a field that tracks who changes a status, to what, and when.
Instead of creating multiple Change value actions, you can use a formula in a single action.
Use this formula
UserToName(User()) & " has changed the status to " & [Status]
This formula:
identifies the user
sets the field value
uses in the value of the status field
calculates a value for the Status Change Log field
Tip
Use the controls under the formula builder to add relevant fields and the browse functions you can add to a formula.
Learn more about using the formula builder.