Why advanced patterns solve scale problems in Firebase - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize Firebase in your app.

Firebase

const app = initializeApp({ apiKey: [1] });

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

A"your-api-key"

Bapikey

Capi_key

DyourApiKey

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting quotes around the API key

Using incorrect variable names

You must provide your actual API key as a string to initialize Firebase correctly.

2fill in blank

medium

Complete the code to get a Firestore collection reference.

Firebase

const colRef = collection(db, [1]);

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

Adatabase

B"users"

CuserCollection

DcollectionName

Attempts:

3 left

💡 Hint

Common Mistakes

Using variable names instead of string literals

Missing quotes around collection name

The collection name must be a string representing the Firestore collection you want to access.

3fill in blank

hard

Fix the error in the Firestore query to get documents where age is greater than 18.

Firebase

const q = query(colRef, where("age", [1], 18));

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

A==

B<=

C>

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using equality operator instead of greater than

Using less than or not equal operators

The query should use the greater than operator > to filter ages above 18.

4fill in blank

hard

Fill both blanks to create a batched write that updates two documents.

Firebase

const batch = writeBatch(db);
batch.[1](doc(db, "users", "user1"), { active: false });
batch.[2](doc(db, "users", "user2"), { active: false });
await batch.commit();

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

Aupdate

Bset

Cdelete

Dadd

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'set' which overwrites documents

Using 'delete' which removes documents

Use update to modify existing documents in a batch write.

5fill in blank

hard

Fill all three blanks to create a Firestore security rule that allows read only if user is authenticated and document owner.

Firebase

allow read: if request.auth != null && request.auth.uid == resource.data.[1] && resource.data.[2] == [3];

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

AownerId

BuserId

Crequest.auth.uid

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect field names

Comparing to 'true' instead of user ID

The rule checks that the authenticated user's ID matches the document's ownerId and userId fields.