Room with Coroutines in Android Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a suspend function for inserting a user in the DAO.

Android Kotlin

suspend fun insertUser(user: User) [1]

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

A= insert(user)

B{ /* implementation */ }

C= suspendInsert(user)

D= insertUser(user)

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to assign a function call without suspend keyword.

Using a non-suspend function call inside a suspend function without proper handling.

The suspend function must have a body or delegate to another suspend function. Here, we use a function body placeholder.

2fill in blank

medium

Complete the DAO function to return all users as a Flow.

Android Kotlin

@Query("SELECT * FROM users")
fun getAllUsers(): [1]

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AFlow<List<User>>

BLiveData<List<User>>

CDeferred<List<User>>

DList<User>

Attempts:

3 left

💡 Hint

Common Mistakes

Using List which is synchronous and not reactive.

Using LiveData instead of Flow when working with coroutines.

Using Flow> allows observing the database changes asynchronously with coroutines.

3fill in blank

hard

Fix the error in the suspend DAO function declaration for deleting a user.

Android Kotlin

suspend fun deleteUser(user: User) [1]

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

A{ delete(user) }

B= delete(user)

C= suspendDelete(user)

D{ suspendDelete(user) }

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to assign a function call without suspend keyword.

Using an undefined suspendDelete function.

The suspend function should have a function body calling the delete method. Using curly braces with the call is correct.

4fill in blank

hard

Fill both blanks to define a suspend function that updates a user in the DAO.

Android Kotlin

suspend fun updateUser(user: User) [1] update(user) [2]

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

A{

B}

Csuspend

Dfun

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting curly braces causing syntax errors.

Trying to use 'suspend' or 'fun' inside the function body.

The suspend function must have curly braces around the update call to define its body.

5fill in blank

hard

Fill all three blanks to create a DAO function that returns a Flow of users filtered by age.

Android Kotlin

@Query("SELECT * FROM users WHERE age [1] :minAge")
fun getUsersOlderThan(minAge: Int): [2] = [3]

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

A>

BFlow<List<User>>

Cflow { emitAll(query(minAge)) }

DList<User>

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong comparison operator like '<'.

Returning List instead of Flow>.

Not returning a Flow implementation.

The query uses '>' to filter users older than minAge. The function returns a Flow of user lists, implemented by emitting all results from a query flow.