Why Firebase accelerates Android development in Android Kotlin - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize Firebase in an Android app.

Android Kotlin

FirebaseApp.[1](this)

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AinitializeApp

BstartApp

CcreateApp

DlaunchApp

Attempts:

3 left

💡 Hint

Common Mistakes

Using methods like startApp or launchApp which do not exist.

The method initializeApp sets up Firebase in your Android app.

2fill in blank

medium

Complete the code to get a reference to the Firebase Realtime Database.

Android Kotlin

val database = FirebaseDatabase.[1]()

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Ainitialize

BgetReference

Cconnect

DgetInstance

Attempts:

3 left

💡 Hint

Common Mistakes

Using getReference directly without getting the instance first.

getInstance() returns the Firebase Realtime Database instance.

3fill in blank

hard

Fix the error in the code to write data to Firebase Realtime Database.

Android Kotlin

database.[1]("users").setValue(user)

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AgetReference

Breference

Cchild

Dref

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'getReference' which returns the root reference, not a child path.

Using 'reference' or 'ref' which are not valid methods here.

The correct method to get a child reference in the database is child.

4fill in blank

hard

Fill both blanks to read data from Firebase Realtime Database asynchronously.

Android Kotlin

database.[1]("messages").addListenerForSingleValueEvent(object : ValueEventListener {
  override fun onDataChange(snapshot: DataSnapshot) {
    val data = snapshot.[2]()
  }
  override fun onCancelled(error: DatabaseError) {}
})

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AgetReference

BgetValue

CgetData

DfetchValue

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent methods like getData or fetchValue.

Use getReference to point to the path, and getValue() to get the data snapshot value.

5fill in blank

hard

Fill all three blanks to authenticate a user with Firebase using email and password.

Android Kotlin

FirebaseAuth.[1]().[2](email, password).addOnCompleteListener { task ->
  if (task.[3]()) {
    // User signed in
  }
}

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AgetInstance

BsignInWithEmailAndPassword

CisSuccessful

DcreateUserWithEmailAndPassword

Attempts:

3 left

💡 Hint

Common Mistakes

Using createUserWithEmailAndPassword instead of signInWithEmailAndPassword for signing in.

Use getInstance() to get FirebaseAuth, then signInWithEmailAndPassword to sign in, and check isSuccessful() on the task.