Developer Fundamentals Flashcards

Which Lightning Web Component lifecycle hook fires after every render of the component, including the initial render?

Answer: renderedCallback()

renderedCallback() is called after every render cycle, both the initial render and subsequent re-renders due to property changes.

In LWC, how does a child component pass data up to a parent component?

Answer: By dispatching a custom event that the parent listens to

Child components communicate upward by dispatching CustomEvent objects, which parent components handle using event listener syntax in the template.

What is the purpose of the @api decorator in a Lightning Web Component?

Answer: It exposes a property or method as public, allowing parent components to set it

The @api decorator makes a property or method publicly accessible, allowing parent components or App Builder admins to pass values in.

Which Aura component attribute enables two-way data binding between a component and its parent?

Answer: {!v.attributeName}

The {!v.attributeName} expression syntax in Aura enables two-way data binding between a component's view value provider and its template.

A developer needs to call an Apex method from LWC that should NOT be cached. Which wire adapter approach is correct?

Answer: Use an imperative Apex call (import and call as a function) instead of @wire

Imperative Apex calls always fetch fresh data from the server, while @wire is designed for cacheable methods and may return cached results.

What is the correct way to reference a static resource in a Lightning Web Component JavaScript file?

Answer: import myResource from '@salesforce/resourceUrl/MyResourceName'

Static resources are imported in LWC using the @salesforce/resourceUrl scoped module import syntax.

Which LWC feature allows a component to subscribe to messages published by other components without a direct parent-child relationship?

Answer: Lightning Message Service (LMS)

Lightning Message Service enables communication between components in different parts of the DOM (including Visualforce and Aura) via a named message channel.