Q: How do you handle multiple templates in LWC?
A: You handle multiple templates by using conditional rendering with template tags and lwc:if, lwc:elseif, and lwc:else directives.
Q: How do you use the lightning-icon component?
A: You use the lightning-icon component by specifying the icon name and optional attributes like size and alternative text, e.g., <lightning-icon icon-name="utility:settings" size="small" alternative-text="Settings"></lightning-icon>.
Q: What is the lightning-input-field component?
A: The lightning-input-field component is used within lightning-record-edit-form to display and edit a single field on a record.
Q: How do you trigger reactivity in an LWC component?
A: Reactivity is triggered automatically when reactive properties (e.g., fields or getters) change, causing the component to re-render.
Q: How do you handle data binding between parent and child components?
A: Data binding is handled by passing data from parent to child using @api decorated properties and from child to parent using custom events.
Q: How do you use template loops in LWC?
A: Template loops are used with the for:each directive to iterate over arrays and render items dynamically, e.g., <template for:each={items} for:item="item"><div key={item.id}>{item.name}</div></template>.
Q: What is the @track decorator and why was it deprecated?
A: The @track decorator was used to mark properties for reactivity. It was deprecated because reactivity is now automatic for all fields in a component.
Q: How do you create a custom template in LWC?
A: You create a custom template by defining HTML markup in the .html file of the component.
Q: How do you navigate to a Visualforce page in LWC?
A: You navigate to a Visualforce page using the NavigationMixin with the type: 'standard__webPage' attribute and specifying the URL.
Q: What is the lightning-formatted-text component?
A: The lightning-formatted-text component is used to display formatted text, supporting basic HTML tags and newlines.
Q: How do you handle conditional class application in LWC?
A: You handle conditional class application using template syntax with ternary operators, e.g., class={condition ? 'class1' : 'class2'}.
Q: How do you use the render method in LWC?
A: The render method can be overridden to programmatically control the template rendered by the component.
Q: How do you implement search functionality with debounce in LWC?
A: You implement debounce in search functionality by using a timer to delay the search execution until the user stops typing for a specified time.
Q: How do you create a custom validation message in LWC?
A: You create a custom validation message by using the setCustomValidity method on input elements and calling reportValidity.
Q: How do you include static resources in LWC?
A: You include static resources by uploading them to Salesforce and referencing them in LWC using @salesforce/resourceUrl.
Q: How do you handle click events in LWC?
A: You handle click events by adding an onclick attribute in the HTML and defining the corresponding handler method in JavaScript.
Q: What is the lightning-badge component?
A: The lightning-badge component is used to create a small badge that can display a label.
Q: How do you create a modal dialog in LWC?
A: You create a modal dialog by using standard HTML and CSS for the modal structure or leveraging SLDS modal classes.
Q: How do you handle dynamic component creation in LWC?
A: You handle dynamic component creation by using the createElement function and appending the created element to the DOM.
Q: How do you define default values for properties in LWC?
A: You define default values for properties by initializing them in the component’s JavaScript class.
Q: How do you implement a drag-and-drop interface in LWC?
A: You implement a drag-and-drop interface using standard HTML5 drag-and-drop API with JavaScript event handling.
Q: How do you use the lightning-progress-bar component?
A: You use the lightning-progress-bar component by specifying its value and optional attributes like variant and size.
Q: How do you manage focus in LWC?
A: You manage focus using standard JavaScript methods like focus() and handling focus-related events.
Q: How do you use import to dynamically load resources in LWC?
A: You use import to dynamically load resources by using the import() function which returns a promise that resolves to the module.
Q: How do you handle component-specific styling in LWC?
A: You handle component-specific styling by defining styles in the component’s .css file, scoped to the component.
Q: How do you pass complex objects between components in LWC?
A: You pass complex objects between components by using properties decorated with @api for child components or custom events for parent components.
Q: How do you use the lightning-accordion-section component?
A: You use the lightning-accordion-section component within a lightning-accordion to create expandable and collapsible sections.
Q: How do you handle multiple records update in LWC?
A: You handle multiple records update by creating a list of records and using the updateRecord or updateRecords function from the lightning/uiRecordApi.
Q: How do you use the lightning-combobox component?
A: You use the lightning-combobox component to create a dropdown list by specifying options and handling selection events.
Q: How do you set up two-way data binding in LWC?
A: Two-way data binding is achieved by handling events from child components to update the parent component’s state, which in turn updates the child component’s properties.
LWC Interview Questions and Answers
LWC Interview Questions and Answers – Part 1