Anonymous authentication in Firebase - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to sign in a user anonymously using Firebase Authentication.

Firebase

firebase.auth().[1]()

Drag options to blanks, or click blank then click option'

AsignInAnonymously

BsignOut

CcreateUserWithEmailAndPassword

DsignInWithEmailAndPassword

Attempts:

3 left

💡 Hint

Common Mistakes

Using signInWithEmailAndPassword instead of signInAnonymously.

Trying to create a user with email and password for anonymous sign-in.

The signInAnonymously() method allows users to sign in without providing credentials.

2fill in blank

medium

Complete the code to check if the current user is signed in anonymously.

Firebase

const user = firebase.auth().currentUser;
if (user && user.[1]) {
  console.log('User is anonymous');
}

Drag options to blanks, or click blank then click option'

AisSignedIn

BisAnonymous

Canonymous

DisGuest

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-existent property like isSignedIn or isGuest.

Checking user.anonymous instead of user.isAnonymous.

The isAnonymous property is true if the user signed in anonymously.

3fill in blank

hard

Fix the error in the code to handle anonymous sign-in errors correctly.

Firebase

firebase.auth().signInAnonymously()
  .then(() => {
    console.log('Signed in anonymously');
  })
  .catch(error => {
    console.error('Error code:', [1]);
  });

Drag options to blanks, or click blank then click option'

Aerror.message

Berror.status

Cerror.code

Derror.reason

Attempts:

3 left

💡 Hint

Common Mistakes

Using error.message instead of error.code for error codes.

Using non-existent properties like error.status or error.reason.

The error.code property contains the error code string from Firebase Authentication.

4fill in blank

hard

Fill both blanks to link an anonymous user to an email/password account.

Firebase

const credential = firebase.auth.EmailAuthProvider.[1](email, password);
firebase.auth().currentUser.[2](credential)
  .then(() => console.log('Account linked'))
  .catch(error => console.error(error));

Drag options to blanks, or click blank then click option'

Acredential

BlinkWithCredential

CsignInWithCredential

DcreateCredential

Attempts:

3 left

💡 Hint

Common Mistakes

Using signInWithCredential instead of linkWithCredential for linking accounts.

Using createCredential which is not a Firebase method.

The EmailAuthProvider.credential() creates a credential object, and linkWithCredential() links it to the current user.

5fill in blank

hard

Fill both blanks to sign out the current user and then sign in anonymously again.

Firebase

firebase.auth().[1]()
  .then(() => firebase.auth().[2]())
  .then(() => console.log('Signed out and signed in anonymously'))
  .catch(error => console.error(error));

Drag options to blanks, or click blank then click option'

AsignOut

BsignInAnonymously

CsignInWithEmailAndPassword

DcreateUserWithEmailAndPassword

Attempts:

3 left

💡 Hint

Common Mistakes

Using signInWithEmailAndPassword instead of signInAnonymously for anonymous sign-in.

Not signing out before signing in anonymously again.

First, signOut() signs out the current user, then signInAnonymously() signs in anonymously again.