SALESFORCE-PD1 User Interface Practice Test 3 — 15 Questions

Question 1

Which SLDS grid class should be used to create a flexible container where items wrap automatically onto multiple rows?

Accepted Answer

slds-wrap. slds-wrap enables wrapping in SLDS flexbox grids.

Answer

slds-col

Answer

slds-nowrap

Answer

slds-grid

Question 2

A developer is creating a Lightning Web Component and needs to iterate over a list of items in the HTML template. Which directive should be used?

Accepted Answer

for:each. for:each is the standard directive for looping in LWC templates.

Answer

repeat:for

Answer

apex:repeat

Answer

aura:iteration

Question 3

A developer is writing a Visualforce page with custom controller logic and needs to ensure that database operations are executed transactionally. What happens by default when an unhandled exception occurs during a controller action method?

Accepted Answer

The entire transaction is rolled back.. All database changes in the transaction are rolled back automatically by the platform if an unhandled exception occurs.

Answer

The user is redirected to the login page.

Answer

Only partial records are saved; successful ones are committed.

Answer

Changes are committed and an email is sent to the admin.

Question 4

A developer is implementing a Lightning Web Component that handles drag-and-drop functionality. Which native DOM event is typically intercepted to allow a drop action on an element?

Accepted Answer

dragover and preventDefault(). Preventing default on dragover is required to allow a drop event to fire on an element.

Answer

dragstart

Answer

dropstart

Answer

mousedown

Question 5

A developer has a Lightning Web Component with a reactive property 'recordId'. How should the property be decorated to ensure it receives the current record ID when placed on a record page?

Accepted Answer

@api recordId;. @api makes properties public so the container can pass values like recordId into the component.

Answer

@wire recordId;

Answer

@track recordId;

Answer

@wire(getRecord) recordId;

Question 6

A developer needs to access a specific HTML element in a Lightning Web Component template imperatively. Which method should be called?

Accepted Answer

this.template.querySelector(). this.template.querySelector() is used to query elements inside the component's shadow DOM template.

Answer

window.findElement()

Answer

this.findElement()

Answer

document.querySelector()

Question 7

Which tag is used in Visualforce to include custom CSS stylesheets?

Accepted Answer

. is used to include external CSS files in Visualforce.

Answer

Answer

<apex:css>

Answer

<apex:style>

Question 8

What is the maximum number of view state bytes allowed in a Visualforce page before Salesforce throws an error?

Accepted Answer

172 KB. The maximum view state limit for a Visualforce page is 172 KB.

Answer

1 MB

Answer

64 KB

Answer

512 KB

Question 9

A developer is writing an Aura component and needs to dynamically create a component at runtime. Which JavaScript method should be used?

Accepted Answer

$A.createComponent(). $A.createComponent() is used to instantiate components dynamically in Aura client-side controllers.

Answer

document.createElement()

Answer

Aura.create()

Answer

component.new()

Question 10

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?

Accepted Answer

checkValidity(). checkValidity() evaluates validity and reports validity status on input components.

Answer

verify()

Answer

isValid()

Answer

validate()

Question 11

Which base component should be used in LWC to display a tabular grid of data with sorting and row selection?

Accepted Answer

lightning-datatable. lightning-datatable is the standard component for tabular data display in LWC.

Answer

lightning-grid

Answer

lightning-table

Answer

apex:pageBlockTable

Question 12

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?

Accepted Answer

transient. transient keyword prevents variables from being saved in the view state.

Answer

private

Answer

static

Answer

final

Question 13

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?

Accepted Answer

onmyevent={handler}. Child events are listened to using on<eventname> attribute syntax in the parent template.

Answer

event-myevent={handler}

Answer

on-myevent={handler}

Answer

listener={handler}

Question 14

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?

Accepted Answer

lightning-formatted-number. lightning-formatted-number with format-style="currency" or lightning-formatted-text is used for formatting.

Answer

lightning-input

Answer

apex:outputText

Answer

ui:outputCurrency

Question 15

A developer is working with a Lightning Web Component and needs to ensure reactive updates occur when an object property or array element changes inside a tracked property. What is the correct approach in modern LWC?

Accepted Answer

Reassign the property reference (e.g., this.myObj = {...this.myObj}).. Assigning a new object or array reference (mutation via replacement) triggers reactivity in LWC tracked properties.

Answer

Use @track on every inner property.

Answer

Call component.forceUpdate().

Answer

Mutate the nested property directly; LWC automatically deep-tracks all mutations.