PD1 Lightning Components 4

Question 1

Which LWC feature allows a component to receive data from a Lightning Data Service wire adapter without writing Apex?

Accepted Answer

@wire with getRecord from 'lightning/uiRecordApi'

Answer

The getRecord wire adapter from lightning/uiRecordApi retrieves record data using Lightning Data Service, bypassing the need for custom Apex.

Question 2

What is the correct LWC syntax to iterate over a list of items in a template?

Accepted Answer

Answer

LWC requires both for:each to specify the array and for:item to name the iteration variable in the template directive.

Question 3

In LWC, which key directive is REQUIRED when using for:each iteration to help the framework efficiently update the DOM?

Accepted Answer

key={item.Id}

Answer

The key directive with a unique value (like key={item.Id}) is required on iterated elements so LWC can efficiently reconcile the virtual DOM.

Question 4

Which approach correctly prevents an LWC component from accessing the parent component's DOM elements?

Accepted Answer

LWC automatically enforces shadow DOM isolation between components

Answer

LWC uses native shadow DOM (or synthetic shadow DOM on older browsers) by default, automatically encapsulating each component's DOM from others.

Question 5

In the Aura framework, what is the purpose of `<aura:handler name='init'>` with action='{!c.doInit}'?

Accepted Answer

It calls the doInit controller method when the component initializes

Answer

The init event handler in Aura triggers the specified controller action during the component initialization phase, similar to LWC's connectedCallback.

(PD1) Salesforce Certified Platform Developer 1 Practice Test

(PD1) Salesforce Certified Platform Developer 1 Practice Test

PD1 Lightning Components 4