SF-PD2 User Interface Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Import ShowToastEvent from lightning/platformShowToastEvent and dispatch it with new ShowToastEvent({ title, message, variant }).

  Why this is correct

  The ShowToastEvent module is imported from lightning/platformShowToastEvent. Creating a new instance with title, message, and variant properties and dispatching it via this.dispatchEvent displays a toast in Lightning Experience and the Salesforce mobile app. This is the standard, supported way to show toasts from an LWC.

• ✗

  Use the lightning-toast base component and set its title, message, and variant attributes in the template.

  Why it's wrong here

  There is no lightning-toast base component in the Lightning Web Components library. Toasts are not rendered declaratively; they are triggered by dispatching a ShowToastEvent. Using a non-existent component would result in a template compilation error, and even if it existed, it would not integrate with the platform toast service.

• ✗

  Import toast from lightning/toast and call toast.show({ title, message, variant }).

  Why it's wrong here

  There is no lightning/toast module in the Lightning Web Components framework. The correct module is lightning/platformShowToastEvent, and toasts are shown by dispatching an event, not by calling a show method. This import would fail at build time or runtime, so the toast would never appear.

• ✗

  Import ShowToastEvent from lightning/platformShowToastEvent and call this.ShowToastEvent({ title, message, variant }) without dispatching.

  Why it's wrong here

  ShowToastEvent is a class that must be instantiated with new and then dispatched. Calling it as a method on the component does not create or dispatch an event, so no toast appears. The event must be dispatched through the component's dispatchEvent method to bubble up to the Lightning Experience toast container.