SALESFORCE-PD1 User Interface — 30 Questions

Question 1

A Lightning Web Component needs to communicate an event to a grandparent component that is several levels up in the DOM tree. Which mechanism should be used?

Accepted Answer

CustomEvent with bubbles: true and composed: true. Lightning Message Service (LMS) allows communication across the DOM, including between components that are not in a parent-child relationship.

Answer

Standard component events via aura:registerEvent

Answer

Standard window.postMessage API

Answer

Imperative Apex method calls

Question 2

A developer is building an Aura component and needs to ensure that a client-side controller method executes after the component's DOM has been fully rendered. Which Aura lifecycle event or method should be utilized?

Accepted Answer

aura:doneRendering. The afterRender method in an Aura renderer overrides the default rendering behavior and executes code after rendering.

Answer

init event

Answer

afterDOMInsert

Answer

render event

Question 3

A developer writes an Apex controller for a Visualforce page and wants to paginate through a large list of records using standard controller methods. Which property should be used?

Accepted Answer

ApexPages.StandardController. setCon (ApexPages.StandardSetController) provides standard pagination methods like getPageNumber(), next(), and previous().

Answer

Database.QueryLocator

Answer

ApexPages.Paginator

Question 4

Which TWO statements are true regarding Aura components and Lightning Web Components interoperability? Choose 2 answers.

Accepted Answer

An Aura component can include a Lightning Web Component in its markup.. Aura components can wrap Lightning Web Components, but LWC cannot contain Aura components.

Answer

A Lightning Web Component can include an Aura component in its markup.

Answer

Aura components use the shadow DOM natively just like LWC.

Answer

LWC components must be wrapped in an aura:application to run.

Question 5

A developer needs to retrieve Salesforce data in a Lightning Web Component without writing imperative Apex. Which module should be imported to use the wire service for standard record data?

Accepted Answer

lightning/uiRecordApi. lightning/uiRecordApi provides wire adapters to get, create, update, or delete record data.

Answer

lightning/platformShowErrorToast

Answer

lightning/navigation

Answer

lightning/apex

Question 6

A developer creates a Visualforce page and wants to include standard Salesforce styling. Which attribute on the <apex:page> tag enables this?

Accepted Answer

standardStylesheets="true". The standardStylesheets attribute controls whether standard Salesforce styling is applied.

Answer

lightningStylesheets="true"

Answer

applyHtmlTag="true"

Answer

sidebar="true"

Question 7

A developer creates a custom LWC that wraps child components. The developer needs to pass styling from the parent component into specific slots of the child component. Which CSS selector should be used inside the child component to style content passed into a slot?

Accepted Answer

::slotted(). The ::slotted() pseudo-class selector is used in the child component's stylesheet to target nodes slotted into a <slot> element.

Answer

:content

Answer

:scope

Answer

:host

Question 8

A developer is writing an Aura component and needs to handle an event fired by a child component. Which attribute is required in the aura:handler tag on the parent component?

Accepted Answer

event. The event attribute on aura:handler specifies the event name to handle.

Answer

name

Answer

method

Answer

controller

Question 9

A developer wants to style a Lightning Web Component using the Salesforce Lightning Design System (SLDS). What is the recommended way to include SLDS styling?

Accepted Answer

Use standard SLDS utility classes directly in the component's HTML template.. LWC natively incorporates SLDS styling when using standard base components, but custom styling should use standard SLDS CSS utility classes.

Answer

Import the full SLDS stylesheet explicitly as a static resource.

Answer

Apply standard Bootstrap classes to match Salesforce themes.

Answer

Use inline styles exclusively for all components.

Question 10

A developer is building a Lightning Web Component and needs to execute code as soon as the component is inserted into the DOM. Which lifecycle hook should be used?

Accepted Answer

connectedCallback. connectedCallback() is invoked when a component is inserted into the DOM.

Answer

renderedCallback

Answer

constructor

Answer

disconnectedCallback

Question 11

An LWC component uses a wire adapter to fetch account records. The developer needs to update the parameters passed to the wire adapter dynamically based on user input. How should this be implemented?

Accepted Answer

Mark the property as @track and reference it in a reactive wire property or function.. Using a getter property or tracked reactive property referenced in a @wire decorator allows dynamic parameter updates.

Answer

Call the wire adapter imperatively inside a JavaScript function.

Answer

Use standard hidden HTML inputs to store state.

Answer

Reload the entire browser page using window.location.reload().

Question 12

Which SLDS utility class should a developer use to add a standard margin around a container?

Accepted Answer

slds-m-around_medium. SLDS spacing classes follow the pattern slds-m-{sides}-{size}.

Answer

slds-grid

Answer

slds-padding_medium

Answer

slds-margin-all

Question 13

A developer creates a Lightning Web Component that includes a third-party JavaScript library loaded via a Static Resource. In which lifecycle hook should the third-party library be initialized?

Accepted Answer

connectedCallback. Third-party scripts loaded via loadScript should be initialized in connectedCallback or renderedCallback, typically after successful promise resolution.

Answer

disconnectedCallback

Answer

renderedCallback

Answer

constructor

Question 14

A developer is working with a Lightning Web Component and needs to access a child component's public method from the parent component. How is this achieved?

Accepted Answer

Invoke the method directly on the child element reference obtained via template.querySelector().. Public methods on child components must be decorated with @api and invoked via this.template.querySelector().methodName().

Answer

Bind the child method to a public @api property on the parent.

Answer

Fire an application event from the parent to the child.

Answer

Use document.getElementById() to find the child element.

Question 15

Which lifecycle hook in a Lightning Web Component is called after every render of the component?

Accepted Answer

renderedCallback. renderedCallback() is called after every render of the component, useful for DOM manipulation after rendering.

Answer

constructor

Answer

connectedCallback

Answer

errorCallback

Question 16

A developer needs to navigate to a record detail page from a Lightning Web Component. Which service should be used?

Accepted Answer

lightning/navigation. NavigationMixin from lightning/navigation is used for navigation in LWCs.

Answer

lightning/pageReference

Answer

window.location.href

Answer

lightning/uiRecordApi

Question 17

A developer is building a Visualforce page that uses a custom controller and needs to display a message to the user when an error occurs. Which class and method should be used?

Accepted Answer

ApexPages.addMessage(). ApexPages.addMessage() adds an ApexPages.Message to the page messages list.

Answer

ApexPages.currentPage().getParameters().put()

Answer

Database.addError()

Answer

System.debug()

Question 18

A developer is writing a custom wire adapter or working with custom data in LWC and needs to manually provision data or force a refresh of wire data. Which function should be imported from lightning/uiRecordApi or related wire modules?

Accepted Answer

refreshApex. refreshApex is used to imperatively refresh data provisioned by an Apex wire adapter.

Answer

reloadRecord

Answer

updateRecordCache

Answer

getRecordRefresh

Question 19

What is the correct file extension for a Lightning Web Component HTML template file?

Accepted Answer

.html. LWC HTML template files must use the .html extension and share the component base name.

Answer

.vfp

Answer

.page

Answer

.cmp

Question 20

Which tag is used in Visualforce to iterate over a collection of records and display them in a table?

Accepted Answer

apex:pageBlockTable. or are used for tabular iteration.

Answer

<apex:repeat>

Answer

apex:iterator

Answer

apex:outputPanel