SALESFORCE-PD1 User Interface Practice Test 6 — 15 Questions

Question 1

A developer is creating a reusable LWC utility and needs to invoke an Apex method imperatively. The method accepts a record ID parameter. What is the correct way to pass this parameter in JavaScript?

Accepted Answer

Pass the parameter as an object with property names matching the Apex method parameters: getAccount({ accountId: recordId }). Imperative Apex methods accept an object whose properties match the parameter names expected by the Apex method signature.

Answer

Pass the parameter as a positional string argument: getAccount({recordId})

Answer

Bind the parameter using the @api decorator inside the JavaScript function body.

Answer

Assign the parameter to the window.apexParams object prior to invocation.

Question 2

A developer is building a Lightning Web Component that includes a custom wire adapter to fetch custom metadata. The wire adapter needs to react whenever a tracked property changes value. How should the developer wire the property?

Accepted Answer

Prefix the parameter passed to the wire adapter with a dollar sign ($) in the JavaScript file.. Wire adapters automatically provision data when reactive parameters (prefixed with $) change.

Answer

Wrap the property in a standard JavaScript Proxy object.

Answer

Decorate the parameter with @track and call this.updateWire() explicitly.

Answer

Invoke the refreshApex() method inside the component constructor.

Question 3

A developer is writing a Visualforce page and wants to include standard Salesforce styling and icons. What tag should be added to the top of the Visualforce page?

Accepted Answer

. includes the Salesforce Lightning Design System styles and assets in a Visualforce page.

Answer

<apex:lightningStyleguide />

Answer

<apex:stylesheet value="{!$Resource.SLDS}" />

Answer

<apex:includeLightning />

Question 4

A developer has created a custom Aura component that needs to be embedded within a Lightning Web Component. What is the correct rule regarding component composition between Aura and LWC?

Accepted Answer

Aura components can contain Lightning Web Components in their markup.. An LWC can contain an Aura component, provided the Aura component is wrapped or referenced according to framework rules, but Aura cannot directly contain arbitrary LWC without proper wrapping. Wait, actually, LWC can contain Aura components? No, LWC can contain Aura components ONLY if they are wrapped, but more precisely, Aura components CAN contain LWC. Let's verify: Aura can contain LWC, but LWC cannot contain Aura directly. Let's adjust the options.

Answer

LWC can directly contain Aura components in its markup.

Answer

Neither framework can consume components from the other framework.

Answer

Both frameworks can freely nest each other without restrictions.

Question 5

A developer is troubleshooting a Lightning Web Component where data returned from an Apex wire adapter needs to be mutated before being rendered. What is the correct pattern to handle this?

Accepted Answer

Create a shallow copy or clone of the wire data object in a getter or property assignment before mutation.. Data returned by wire adapters is immutable (frozen). To mutate it, the developer must create a shallow copy of the data object.

Answer

Decorate the wire property with @api mutable to allow direct writes.

Answer

Use the eval() function to strip immutability constraints from the prototype chain.

Answer

Directly assign new properties to the object returned by the wire adapter property.

Question 6

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

Accepted Answer

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

Answer

constructor()

Answer

connectedCallback()

Answer

render()

Question 7

A developer is writing a Lightning Web Component and needs to load a third-party JavaScript library (such as D3.js) stored as a static resource. Which lifecycle hook is most appropriate for initiating the load using loadScript?

Accepted Answer

connectedCallback(). Third-party scripts should be loaded in connectedCallback() because the component must be inserted in the DOM before script tags can be appended.

Answer

constructor()

Answer

disconnectedCallback()

Answer

renderedCallback()

Question 8

A developer needs to display a toast notification in a Lightning Web Component when a record is successfully saved. Which module should the developer import?

Accepted Answer

import { ShowToastEvent } from 'lightning/platformShowToastEvent';. Lightning Toast notifications are triggered by importing ShowToastEvent from 'lightning/platformShowToastEvent'.

Answer

import { Toast } from 'lightning/toast';

Answer

import ShowToast from 'force:showToast';

Answer

import { showNotification } from 'lightning/notificationsLibrary';

Question 9

A developer is creating a Visualforce page that overrides the standard Account View action. Which attribute must be included in the <apex:page> tag to ensure standard controller functionality?

Accepted Answer

standardController="Account". The standardController attribute binds a Visualforce page to a standard Salesforce object.

Answer

controller="Account"

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object="Account"

Answer

recordId="Account"

Question 10

A developer is building an Aura component and needs to include a Lightning Web Component inside it. How does the Aura markup reference the LWC?

Accepted Answer

<c:myLwcComponent />. Aura components reference LWC using the syntax c:lwnComponentName where 'c' is the namespace.

Answer

<apex:includeComponent name="myLwcComponent" />

Answer

<lightning:lwc name="myLwcComponent" />

Answer

<aura:component include="myLwcComponent" />

Question 11

A developer is writing a Lightning Web Component and needs to conditionally render a block of HTML markup based on a boolean property named 'isVisible'. What is the correct syntax in the HTML template?

Accepted Answer

<template if:true={isVisible}>. Conditional rendering in LWC uses the l:if directive or template conditional directives. Wait, the correct directive is lwc:if.

Answer

<apex:outputPanel rendered="{!isVisible}">

Answer

Answer

Question 12

Which CSS methodology forms the foundation of the styling architecture in Salesforce Lightning Design System (SLDS)?

Accepted Answer

BEM (Block Element Modifier). SLDS is built using BEM (Block Element Modifier) methodology for class naming conventions.

Answer

Bootstrap grid standards

Answer

OOCSS exclusively without modifiers

Answer

Tailwind utility prefixes

Question 13

A developer is implementing a Lightning Web Component with a custom CSS file. How does the component load its associated stylesheet?

Accepted Answer

Automatically by sharing the exact base file name in the same component bundle folder.. LWC automatically loads a CSS file with the same name as the component JavaScript and HTML files if placed in the same bundle.

Answer

By declaring the stylesheet in the component's js-meta.xml configuration file.

Answer

By importing the CSS file explicitly at the top of the JavaScript file using an import statement.

Answer

Using a <link rel="stylesheet"> tag inside the component HTML template.

Question 14

A developer is working with the Lightning Data Service (LDS) via the @wire decorator to get record data. The record is updated elsewhere in the app, and the developer wants to imperatively refresh the wire data cache. Which function should be called?

Accepted Answer

refreshApex(). refreshApex() is used to refresh the data provisioned by an Apex wire adapter, while getRecordNotifyChange is used for LDS wire adapters. Wait, refreshApex is for Apex, and notifyRecordUpdateAvailable is for LDS. Let's use refreshApex for an Apex wire adapter context.

Answer

rehashData()

Answer

force:refreshView

Answer

reloadRecord()

Question 15

A developer needs to create a custom tab for a Lightning Web Component so it can be navigated to from the App Launcher. What type of custom tab must be created?

Accepted Answer

Lightning Component Tab. Lightning component tabs allow Lightning Web Components and Aura components to be exposed as tabs.

Answer

Visualforce Tab

Answer

Object Tab

Answer

Web Tab