To replace a JavaScript button from Salesforce Classic that creates records with prepopulated values in Lightning Experience, the developer can use:
Option A: Quick Actions
Quick Actions (Specifically, Object-Specific Actions):
Quick Actions allow users to perform actions, such as creating or updating records, from a record page or global context.
Prepopulating Fields:
You can predefine field values in Quick Actions using predefined values or by utilizing Lightning Component actions.
Reference:
"You can set predefined values for fields on the action layout, which lets you specify default values for the new record."
- Salesforce Help: Predefined Field Values for Quick Actions
Why Other Options Are Less Suitable:
Option B: Validation Rules
Validation rules enforce data integrity but do not create records or prepopulate values.
Option C: Record-Triggered Flows
Flows can automate processes but are not a direct replacement for buttons that create records with prepopulated values from the UI.
Option D: Apex Triggers
Triggers execute logic in response to DML events but are not used to create UI components or replace buttons.
Conclusion:
Quick Actions are the recommended way to replicate the functionality of JavaScript buttons in Lightning Experience.