PD1 Lightning Components 2

Question 1

Which lifecycle hook in a Lightning Web Component is called every time the component is inserted into the DOM?

Accepted Answer

connectedCallback()

Answer

connectedCallback() fires each time the component is inserted into the DOM, making it ideal for setup logic that depends on the component being in the page.

Question 2

In Aura components, which attribute type allows a component to accept a JavaScript function as a parameter from a parent component?

Accepted Answer

Action

Answer

The Action attribute type in Aura allows a component to receive a controller action reference, enabling parent-to-child method passing.

Question 3

What is the correct way to call an Apex method imperatively in a Lightning Web Component?

Accepted Answer

import apexMethod from '@salesforce/apex'; apexMethod().then(...)

Answer

Imperative Apex calls in LWC use the imported method as a regular JavaScript function that returns a Promise.

Question 4

Which decorator in LWC makes a property reactive so that changes trigger a re-render?

Accepted Answer

@track

Answer

@track makes an object or array's nested properties reactive in LWC; primitive @api properties are already reactive.

Question 5

In a Lightning Web Component, where must you define a public property that a parent component can set?

Accepted Answer

Using @api in the JS file

Answer

@api exposes a property or method as part of the component's public API, allowing parent components to pass values in.

(PD1) Salesforce Certified Platform Developer 1 Practice Test

(PD1) Salesforce Certified Platform Developer 1 Practice Test

PD1 Lightning Components 2