The Complete React Developer Course (with Hooks and Redux) - Fetching Data from Firebase

This video tutorial covers how to fetch data from Firebase using two main methods: fetching data once with the 'once' method and setting up subscriptions with the 'on' method. It explains how to handle data changes and unsubscribe from them using the 'off' method. The tutorial includes a practical challenge to reinforce learning and concludes with a summary of the key concepts.

What are the two main methods to fetch data from Firebase discussed in the video?

• Fetching data using REST API and GraphQL

• Fetching data once and setting up a subscription

• Using SQL queries and NoSQL queries

• Using local storage and session storage

Which method is used to fetch data from Firebase a single time?

• fetch

• once

• on

• get

What does the 'once' method return when fetching data?

• A promise

• A synchronous result

• A callback function

• An observable

Why are promises not suitable for handling data changes in real-time?

• They require too much memory

• They do not support asynchronous operations

• They are too slow

• They can only be resolved or rejected once

Which method allows you to listen for data changes over and over again?

• fetch

• once

• on

• listen

What is the purpose of the 'off' method in Firebase?

• To fetch data once

• To unsubscribe from data changes

• To delete data

• To update data

How can you unsubscribe from a specific subscription in Firebase?

• By passing the subscription ID to 'off'

• By passing the exact same function to 'off'

• By calling 'unsubscribe' method

• By deleting the reference

What happens when you pass nothing to the 'off' method?

• It throws an error

• It removes all subscriptions

• It does nothing

• It fetches data once

In the challenge, what message should be printed using the subscription data?

• Andrew is a software developer at Amazon

• John is a data scientist at Facebook

• Mike is a software developer at Google

• Sarah is a project manager at Microsoft

What is the main focus of the next video after this one?

• How to structure data in Firebase for a real-world application

• How to use Firebase authentication

• How to deploy a Firebase app

• How to integrate Firebase with third-party APIs