Firebase Authentication in Flutter - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Firebase Authentication used for in a mobile app?

Firebase Authentication helps you add sign-in and user identity management easily, so users can log in securely using email, phone, or social accounts.

beginner

Which Flutter package is commonly used to integrate Firebase Authentication?

The package firebase_auth is used to add Firebase Authentication features in Flutter apps.

intermediate

How do you sign in a user with email and password using Firebase Authentication in Flutter?

Use FirebaseAuth.instance.signInWithEmailAndPassword(email: email, password: password) to sign in a user.

intermediate

What is the purpose of FirebaseAuth.instance.currentUser in Flutter?

It returns the currently signed-in user, or null if no user is signed in. Useful to check login state.

beginner

Why is it important to handle errors when using Firebase Authentication?

Because sign-in can fail for many reasons (wrong password, network issues), handling errors helps show friendly messages and keep the app stable.

Which method signs in a user with email and password in Firebase Authentication for Flutter?

A signOut

B createUserWithEmailAndPassword

C signInAnonymously

D signInWithEmailAndPassword

signInWithEmailAndPassword is used to log in existing users with email and password.

What does FirebaseAuth.instance.currentUser return if no user is signed in?

A An empty user object

B null

C An error

D A guest user

It returns null when no user is signed in.

Which Flutter package do you add to use Firebase Authentication?

A firebase_auth

B firebase_database

C firebase_core

D cloud_firestore

firebase_auth is the package for Firebase Authentication.

What is a common reason to handle errors during sign-in?

A To improve app speed

B To change user password automatically

C To show friendly messages if sign-in fails

D To update the UI theme

Handling errors helps show clear messages when sign-in fails.

Which Firebase Authentication method creates a new user with email and password?

A createUserWithEmailAndPassword

B sendPasswordResetEmail

C signInWithCredential

D signInWithEmailAndPassword

createUserWithEmailAndPassword registers a new user.

Explain how to implement email/password sign-in using Firebase Authentication in Flutter.

Think about the steps from setup to calling the sign-in method.

Describe how to check if a user is currently signed in using Firebase Authentication in Flutter.

Focus on the property that holds the current user info.