75 of 122 questions · Page 1/2 · User Interface · Answers revealed
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?
Correct because <apex:slds /> includes SLDS resources in Visualforce.
Why this answer
<apex:slds /> includes the Salesforce Lightning Design System styles and assets in a Visualforce page.
Which lifecycle hook in a Lightning Web Component is called after every render of the component?
Called after every render of the component.
Why this answer
renderedCallback() is called after every render of the component, useful for DOM manipulation after rendering.
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?
Reactive properties in wire arguments cause the wire to re-provision data when changed.
Why this answer
Using a getter property or tracked reactive property referenced in a @wire decorator allows dynamic parameter updates.
A developer is building a Lightning Web Component and wants to define a property that can be set by a parent component. Which decorator is required?
Correct because @api exposes public properties to parent components.
Why this answer
The @api decorator exposes a public property or method, making it accessible to parent components.
Which THREE statements are true regarding the standard Salesforce Lightning Design System (SLDS)? Choose 3 answers.
Correct. The platform automatically includes SLDS styling context for Lightning components.
Why this answer
SLDS is built into the Salesforce platform, provides CSS framework styling matching the Salesforce look-and-feel, and can be used in both LWC and Visualforce.
A developer is writing a Visualforce page and wants to display messages generated by controllers or validation rules. Which component should be used?
Correct because <apex:pageMessages> renders system and custom error messages.
Why this answer
<apex:pageMessages /> displays all messages queued on the page for the current request.
Which TWO statements are true regarding the differences between Aura components and Lightning Web Components (LWC)? (Choose TWO)
Correct because LWC leverages standard web components and modern ECMAScript.
Why this answer
LWC builds on native web standards and modern JS, whereas Aura relies on an older framework architecture.
Which THREE features or capabilities are supported by the Lightning Message Service (LMS)? Choose 3 answers.
LMS enables publisher-subscriber pattern across the page.
Why this answer
LMS supports communication across DOM boundaries, between Visualforce, Aura, and LWC.
A developer is configuring a Lightning Web Component to be used as a Quick Action on a record page. Which target configuration must be added to the component's metadata file?
Enables the component as a record quick action.
Why this answer
lightning__RecordAction enables a component to be used as a record-level quick action.
A developer is building a Visualforce page and wants to execute an action method on the controller when a user clicks a button, without performing a full page reload. Which component should be wrapped around the area to be updated?
Enables AJAX partial page rendering.
Why this answer
<apex:actionRegion> or <apex:outputPanel> with <apex:actionSupport> or <apex:commandButton rerender=...> performs partial page updates.
A developer is troubleshooting an issue where a Lightning Web Component is not picking up changes to the internal fields of an object property. What is the cause of this behavior in LWC reactivity?
Correct because LWC tracks changes at the reference level for plain objects unless observed via @track.
Why this answer
LWC reactivity is shallow; mutating properties of a nested object without reassigning the reference requires @track or creating a new object reference.
Which TWO tools or features are recommended for styling Lightning Web Components according to best practices? Choose 2 answers.
LWC automatically scopes CSS styles defined in a companion .css file.
Why this answer
SLDS utility classes and scoped CSS stylesheets are the standard ways to style LWC.
A developer creates a Visualforce page and wants to include standard Salesforce styling. Which attribute on the <apex:page> tag enables this?
Includs standard Salesforce styles on the page.
Why this answer
The standardStylesheets attribute controls whether standard Salesforce styling is applied.
A developer is working with component styling and design tokens in Lightning Web Components. Which TWO practices apply when working with SLDS styling in LWC? (Choose TWO)
Correct because SLDS utility classes ensure consistency and theme adaptability.
Why this answer
SLDS design tokens can be used via var() CSS variables, and standard SLDS classes should be preferred over custom CSS where possible.
A developer is building a Lightning Web Component and wants to iterate over a list of items in the HTML template. Which directive should be used?
Correct because for:each is the standard iteration directive in LWC.
Why this answer
Iteration in LWC templates uses the <template for:each={list} for:item={item}> construct.
Which base Lightning component should be used in an LWC to display a standard button?
Standard LWC component for buttons.
Why this answer
lightning-button is the standard base component for buttons in LWC.
A developer needs to create a Lightning Web Component configuration file. What is the required file extension and naming convention?
Correct because .js-meta.xml is the required extension and format for LWC metadata files.
Why this answer
LWC configuration files are named componentName.js-meta.xml.
A developer is using the Lightning Message Service and needs to unsubscribe from a message channel when a component is destroyed. In which lifecycle hook should unsubscribe be called?
Used for cleanup and unsubscription.
Why this answer
disconnectedCallback is used for cleanup tasks like unsubscribing from message channels or removing event listeners when a component is removed from the DOM.
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?
Specifies the fully qualified name of the event.
Why this answer
The event attribute on aura:handler specifies the event name to handle.
Which base Lightning component is used to show a progress indicator or spinner in LWC?
Standard component for loading indicators.
Why this answer
lightning-spinner is the standard component for loading spinners in LWC.
Which TWO tools or environments are officially supported for developing Lightning Web Components? (Choose TWO)
Correct because VS Code is the primary supported IDE for LWC.
Why this answer
Visual Studio Code with the Salesforce Extension Pack and Salesforce CLI are standard tools for LWC development.
A developer creates a parent Lightning Web Component containing a child component. The parent needs to call a public method defined inside the child component. How is this accomplished?
Correct because querying the child component reference allows calling its exported @api methods.
Why this answer
A parent component can invoke a public method on a child component by querying the child element and calling the method directly.
A developer is building a Lightning Web Component and wants to style it using Salesforce Lightning Design System (SLDS). Which TWO statements are true regarding SLDS usage in LWC? (Choose TWO)
Correct because SLDS is natively built into the Lightning Experience platform.
Why this answer
SLDS is natively available in LWC without static resource uploads, and utility classes are used for styling.
A developer is utilizing the Lightning Message Service (LMS) to facilitate communication between an Aura component and a Lightning Web Component. Which THREE steps are required to implement LMS successfully? (Choose THREE)
Correct because Message Channels are defined as metadata files in the force-app directory.
Why this answer
LMS requires defining a Message Channel metadata file, importing the channel in the component, and calling publish or subscribe APIs.
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?
Correct because Aura references LWC using standard kebab-case or camelCase converted to namespace tag syntax.
Why this answer
Aura components reference LWC using the syntax c:lwnComponentName where 'c' is the namespace.
Which TWO conditions must be met for an Apex method to be wired using the @wire service in an LWC? Choose 2 answers.
Wire methods must be static and accessible.
Why this answer
Wired Apex methods must be static, public or global, and annotated with @AuraEnabled(cacheable=true).
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?
Applies styles to elements that are distributed into a slot.
Why this answer
The ::slotted() pseudo-class selector is used in the child component's stylesheet to target nodes slotted into a <slot> element.
A developer is implementing communication in Lightning Web Components. Which TWO mechanisms are valid for passing data or messages between components? (Choose TWO)
Correct because CustomEvent is standard for child-to-parent communication.
Why this answer
Custom events (child to parent) and Lightning Message Service (unrelated components) are standard mechanisms.
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?
Correct because ShowToastEvent is the standard module for displaying toasts.
Why this answer
Lightning Toast notifications are triggered by importing ShowToastEvent from 'lightning/platformShowToastEvent'.
Which tag is used in Visualforce to output field labels and values dynamically based on sObject field definitions?
Renders sObject field data with field-level security and formatting.
Why this answer
<apex:outputField> renders field values with correct formatting and related labels.
A developer is troubleshooting lifecycle hooks and rendering behavior in a Lightning Web Component. Which THREE statements are correct regarding LWC lifecycle execution order? (Choose THREE)
Correct because the constructor initializes the component instance before DOM insertion.
Why this answer
Constructor runs first, then connectedCallback, then renderedCallback after render.
What is the correct syntax to reference a custom label in a Lightning Web Component JavaScript file?
Correct import syntax for LWC JS.
Why this answer
Custom labels are imported from @salesforce/label/Namespace.LabelName.
A developer needs to pass data from a child Lightning Web Component to a parent Lightning Web Component up the component hierarchy. What is the standard mechanism to achieve this?
Correct because CustomEvent is the standard mechanism for child-to-parent communication.
Why this answer
Child-to-parent communication in LWC is achieved by dispatching a custom event using CustomEvent and listening to it in the parent template.
A developer is configuring a Lightning Web Component to accept design attributes in the Lightning App Builder. Which THREE files make up a complete LWC bundle that supports App Builder configuration properties? (Choose THREE)
Correct part of bundle.
Why this answer
A complete configurable LWC bundle includes the HTML template, JavaScript controller, metadata file (.js-meta.xml), and design file (.design).
A developer needs to include a third-party style sheet in a Lightning Web Component. What is the standard way to load CSS styles that are stored as a static resource?
Correct because loadStyle is used to load static resource CSS files.
Why this answer
Third-party stylesheets are loaded using loadStyle from 'lightning/platformResourceLoader' inside connectedCallback.
Which CSS methodology forms the foundation of the styling architecture in Salesforce Lightning Design System (SLDS)?
Correct because SLDS utilizes BEM naming conventions.
Why this answer
SLDS is built using BEM (Block Element Modifier) methodology for class naming conventions.
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?
Correct because refreshApex refreshes the cache for Apex wire adapters.
Why this answer
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.
A developer is building a Lightning Web Component and needs to dispatch a custom event. Which constructor should be used to create the event?
Standard constructor for custom events carrying detail payloads.
Why this answer
CustomEvent is the standard browser constructor used to create custom events in LWC.
A developer is working with a Visualforce page and wants to display a list of Account records using standard styling that matches the Salesforce Classic UI. Which component should the developer include?
Correct because <apex:pageBlockTable> formats tabular data matching the standard Salesforce look and feel.
Why this answer
The <apex:enhancedList> or <apex:relatedList> components allow developers to display lists with standard Salesforce formatting.
Which TWO methods can be used to navigate to a standard Salesforce object's home page from a Lightning Web Component? Choose 2 answers.
Standard navigation mixin type for object pages.
Why this answer
NavigationMixin with standard__objectPage and actionName 'home' navigates to an object's home page.
A Lightning Web Component needs to communicate an event up to a grandparent component that is nested two levels above. What is the best practice to achieve this in LWC?
Correct. Setting bubbles: true allows the event to traverse up the DOM tree to parent and grandparent components.
Why this answer
Custom events in LWC bubble up the DOM tree by default when constructed with { bubbles: true, composed: false }, allowing parent and grandparent components to listen for them.
A developer needs to navigate to a record detail page from a Lightning Web Component. Which service should be used?
Provides navigation service methods.
Why this answer
NavigationMixin from lightning/navigation is used for navigation in LWCs.
A developer wants to conditionally display an HTML element in a Lightning Web Component template based on a boolean property named 'isVisible'. Which directive should be used?
Conditionally renders DOM elements based on a boolean expression.
Why this answer
lwc:if is the modern conditional directive in LWC.
A developer is designing a Lightning Web Component that needs to communicate with another component located anywhere in the application hierarchy, including unrelated components. Which TWO mechanisms are valid and appropriate for this requirement? Choose 2 answers.
Correct. A custom pub/sub utility using EventTarget or custom events allows decoupled components to communicate.
Why this answer
Lightning Message Service (LMS) and custom PubSub patterns built on top of standard browser events or custom event dispatchers are suited for communication across unrelated components.
A developer needs to configure a Lightning Web Component to be available for use on Lightning Record Pages. Which configuration entry must be present in the component's metadata file (.js-meta.xml)?
Enables the component for record pages.
Why this answer
lightning__RecordPage target enables a component to be placed on record pages.
Which tag is used in Visualforce to include custom CSS stylesheets?
Includes a stylesheet in the page.
Why this answer
<apex:stylesheet> is used to include external CSS files in Visualforce.
A developer needs to format a currency value according to the user's locale in a Lightning Web Component HTML template. Which base component should be used?
Supports currency formatting based on user locale.
Why this answer
lightning-formatted-number with format-style="currency" or lightning-formatted-text is used for formatting.
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?
Correct because Lightning Component Tabs expose LWC to the App Launcher and navigation menus.
Why this answer
Lightning component tabs allow Lightning Web Components and Aura components to be exposed as tabs.
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?
Public child methods are callable directly from the parent via the component reference.
Why this answer
Public methods on child components must be decorated with @api and invoked via this.template.querySelector().methodName().
A developer is styling a Lightning Web Component using the Salesforce Lightning Design System (SLDS). To ensure the component adheres to the standard styling guidelines for spacing, what should the developer use?
Correct because SLDS utility classes provide consistent, standardized spacing.
Why this answer
SLDS provides predefined design tokens and CSS utility classes (such asslds-m-around_medium) for consistent spacing.
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?
Correct because Aura components support embedding Lightning Web Components.
Why this answer
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.
Which lifecycle hook in a Lightning Web Component runs after every render of the component?
Correct because renderedCallback runs after every render cycle.
Why this answer
renderedCallback() is called after every render of the component, useful for post-rendering DOM manipulation.
A developer is configuring a Lightning Web Component metadata file to allow the component to be placed on a FlexPage. Which tag defines the configuration regions or design properties?
Correct because design files define attributes exposed in the Lightning App Builder.
Why this answer
The <masterLabel> and <targets> are used, but design properties are defined in a separate design file (.design). Wait, configuration regions for App Builder properties are defined in the .design file for Aura, but in LWC design properties are also in a .design file. Let's frame the question around design files.
A developer is creating a Lightning Web Component that needs to display a list of Accounts. The developer wants to fetch the data imperatively when a user clicks a button rather than automatically via a wire adapter. What is the correct approach?
Correct because imperative Apex is called as a function returning a promise inside an event handler.
Why this answer
Imperative Apex calls are invoked as standard JavaScript promises, typically triggered by an event handler such as a button click.
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?
SLDS classes are available by default in Salesforce environments.
Why this answer
LWC natively incorporates SLDS styling when using standard base components, but custom styling should use standard SLDS CSS utility classes.
Which TWO features are provided out-of-the-box by Visualforce when building standard user interfaces? (Choose TWO)
Correct because standard controllers automatically respect object and field permissions.
Why this answer
Visualforce provides automatic CRUD/FLS enforcement with standard controllers and built-in view state management.
A developer wants to prevent sensitive fields from being included in the Visualforce view state to reduce size. Which keyword should be added to the field declaration in the controller?
Excludes variables from the Visualforce view state.
Why this answer
transient keyword prevents variables from being saved in the view state.
Which TWO configuration files or metadata elements are required when creating a Lightning Web Component? Choose 2 answers.
Defines component logic and class.
Why this answer
Every LWC requires an HTML template file and a metadata configuration XML file.
Which TWO actions can a developer perform using standard Visualforce controllers? Choose 2 answers.
Standard controller built-in actions handle standard DML.
Why this answer
Standard controllers allow basic DML operations like save and delete, and provide access to record fields.
Which SLDS utility class should a developer use to add a standard margin around a container?
Applies a medium margin around all sides of an element.
Why this answer
SLDS spacing classes follow the pattern slds-m-{sides}-{size}.
A developer is creating a Lightning Web Component that needs to interact with Salesforce data using Lightning Data Service. Which TWO wire adapters are natively available in the @salesforce/apex or lightning/ui* modules for basic record operations? (Choose TWO)
Correct because getRecordUi is a standard LDS wire adapter for layout and record data.
Why this answer
getRecord and getRecordUi are standard wire adapters provided by lightning/uiRecordApi for working with Salesforce records.
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?
Correct because standardController specifies the object context.
Why this answer
The standardController attribute binds a Visualforce page to a standard Salesforce object.
A developer is implementing error handling for an imperative Apex call in a Lightning Web Component. Which THREE properties or techniques are standard for catching and inspecting errors returned from Apex promises? (Choose THREE)
Correct because imperative Apex returns a promise that uses .catch for error handling.
Why this answer
Imperative Apex returns promises where errors can be caught in .catch(), inspected via error.body.message, or handled via standard JavaScript error objects.
A developer is reviewing a Lightning Web Component that makes calls to an Apex controller. Which THREE best practices should be followed when designing the Apex methods for LWC consumption? (Choose THREE)
Correct because LWC requires serializable primitives or wrapper structures.
Why this answer
Apex methods for LWC should be cacheable when read-only, handle security/sharing properly, and accept appropriate parameter types.
A developer is building a Lightning Web Component and needs to navigate to a URL that is external to Salesforce. Which PageReference type should be used with NavigationMixin?
Used for external URLs.
Why this answer
standard__webPage is the PageReference type for navigating to external URLs or web pages.
Which TWO lifecycle hooks are available in Lightning Web Components? Choose 2 answers.
Invoked after every render of the component.
Why this answer
connectedCallback and renderedCallback are standard LWC lifecycle hooks.
A developer is building a Lightning Web Component and needs to perform validation on an input field before submission. Which method on a lighting-input element checks validity?
Checks if the input satisfies validity constraints.
Why this answer
checkValidity() evaluates validity and reports validity status on input components.
Which THREE statements are true regarding Lightning Web Component shadow DOM encapsulation? Choose 3 answers.
DOM queries are encapsulated within the component shadow root.
Why this answer
Shadow DOM encapsulates templates, styles, and queries, preventing external CSS bleeding and restricting queries to the component template.
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?
Correct because connectedCallback ensures the component is in the DOM for script loading.
Why this answer
Third-party scripts should be loaded in connectedCallback() because the component must be inserted in the DOM before script tags can be appended.
Which tag is used in Visualforce to iterate over a collection of records and display them in a table?
Renders data in a standard Salesforce styled table format.
Why this answer
<apex:pageBlockTable> or <apex:dataTable> are used for tabular iteration.
Which base component should be used in LWC to display a tabular grid of data with sorting and row selection?
Standard LWC component for structured data tables.
Why this answer
lightning-datatable is the standard component for tabular data display in LWC.
Which tool or feature should a developer use to test Lightning Web Components locally on their workstation without deploying to Salesforce every time?
Correct because the Local Development Server enables local preview.
Why this answer
LWC Local Development Server allows developers to preview components locally.
A developer needs to execute initialization logic as soon as a Lightning Web Component is inserted into the DOM. Which lifecycle hook should be used?
Correct. connectedCallback() runs when the component is inserted into the DOM.
Why this answer
connectedCallback() is invoked when a component is inserted into the DOM, making it the standard hook for initialization logic.
A developer is building a Lightning Web Component and needs to listen to a custom event dispatched by a child component. How is the event listener attached in the parent HTML template?
Standard LWC syntax for listening to custom events (lowercased event name).
Why this answer
Child events are listened to using on<eventname> attribute syntax in the parent template.
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?
Correct because the $ prefix denotes a reactive property that triggers reprovisioning when changed.
Why this answer
Wire adapters automatically provision data when reactive parameters (prefixed with $) change.
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