Retrofit setup in Android Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a Retrofit instance with the base URL.

Android Kotlin

val retrofit = Retrofit.Builder()
    .baseUrl("[1]")
    .build()

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

A"api.example.com"

B"https://api.example.com/"

C"http://api.example.com"

D"https://example.com/api"

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the scheme (http/https) causes errors.

Forgetting the trailing slash at the end of the URL.

The base URL must end with a slash and include the scheme (https://) for Retrofit to work correctly.

2fill in blank

medium

Complete the code to add a JSON converter factory to Retrofit.

Android Kotlin

val retrofit = Retrofit.Builder()
    .baseUrl("https://api.example.com/")
    .addConverterFactory([1].create())
    .build()

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

AGsonConverterFactory

BJsonConverterFactory

CMoshiConverterFactory

DXmlConverterFactory

Attempts:

3 left

💡 Hint

Common Mistakes

Using a converter factory that does not match the data format.

Forgetting to add the converter factory causes parsing errors.

GsonConverterFactory is commonly used to convert JSON data to Kotlin objects in Retrofit.

3fill in blank

hard

Fix the error in the Retrofit builder code by completing the blank.

Android Kotlin

val retrofit = Retrofit.Builder()
    .baseUrl("https://api.example.com/")
    .addConverterFactory(GsonConverterFactory.[1]())
    .build()

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

AgetInstance

Bnew

Cbuild

Dcreate

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'new' keyword which is invalid in Kotlin.

Using 'build' or 'getInstance' which do not exist for this class.

The correct method to get a GsonConverterFactory instance is 'create()'.

4fill in blank

hard

Fill both blanks to define a Retrofit service interface with a GET request.

Android Kotlin

interface ApiService {
    @[1]("users")
    fun getUsers(): [2]<List<User>>
}

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

AGET

BPOST

CCall

DResponse

Attempts:

3 left

💡 Hint

Common Mistakes

Using POST instead of GET for fetching data.

Using Response instead of Call as the return type.

The GET annotation defines a GET request, and Call wraps the response type for Retrofit.

5fill in blank

hard

Fill all three blanks to build a Retrofit instance with base URL, JSON converter, and create the service.

Android Kotlin

val retrofit = Retrofit.Builder()
    .baseUrl([1])
    .addConverterFactory([2].create())
    .build()

val service = retrofit.[3](ApiService::class.java)

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

A"https://api.example.com/"

BGsonConverterFactory

Ccreate

DcreateService

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'createService' instead of 'create' method on retrofit.

Missing quotes around the base URL.

Using wrong converter factory.

Use the correct base URL string, GsonConverterFactory with create(), and Retrofit's create() method to get the service instance.