PD1 Developer Fundamentals 5

Question 1

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

Accepted Answer

renderedCallback()

Answer

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

Question 2

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

Accepted Answer

By dispatching a custom event that the parent listens to

Answer

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

Question 3

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

Accepted Answer

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

Answer

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

Question 4

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

Accepted Answer

{!v.attributeName}

Answer

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

Question 5

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

Accepted Answer

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

Answer

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

(PD1) Salesforce Certified Platform Developer 1 Practice Test