Permission request flow in Android Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if the app has the CAMERA permission.

Android Kotlin

val hasCameraPermission = ContextCompat.checkSelfPermission(this, [1]) == PackageManager.PERMISSION_GRANTED

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

AManifest.permission.CAMERA

BManifest.permission.ACCESS_FINE_LOCATION

CManifest.permission.RECORD_AUDIO

DManifest.permission.READ_CONTACTS

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong permission string like location or contacts.

Forgetting to compare the result to PERMISSION_GRANTED.

We check for the CAMERA permission using Manifest.permission.CAMERA.

2fill in blank

medium

Complete the code to request CAMERA permission from the user.

Android Kotlin

ActivityCompat.requestPermissions(this, arrayOf([1]), REQUEST_CAMERA_CODE)

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

AManifest.permission.CAMERA

BManifest.permission.ACCESS_FINE_LOCATION

CManifest.permission.READ_SMS

DManifest.permission.RECORD_AUDIO

Attempts:

3 left

💡 Hint

Common Mistakes

Requesting a different permission than the one checked.

Not wrapping the permission string inside an array.

We request the CAMERA permission by passing Manifest.permission.CAMERA inside the array.

3fill in blank

hard

Fix the error in the permission result check inside onRequestPermissionsResult.

Android Kotlin

if (requestCode == REQUEST_CAMERA_CODE && grantResults.isNotEmpty() && grantResults[[1]] == PackageManager.PERMISSION_GRANTED) {
    // Permission granted
}

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

A1

B-1

C0

DrequestCode

Attempts:

3 left

💡 Hint

Common Mistakes

Using index 1 or other invalid indices causing crashes.

Comparing with requestCode instead of grantResults.

The first permission result is at index 0 in grantResults.

4fill in blank

hard

Fill both blanks to create a function that checks and requests CAMERA permission if not granted.

Android Kotlin

fun checkCameraPermission() {
    if (ContextCompat.checkSelfPermission(this, [1]) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this, arrayOf([2]), REQUEST_CAMERA_CODE)
    }
}

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

AManifest.permission.CAMERA

BManifest.permission.ACCESS_FINE_LOCATION

DManifest.permission.READ_CONTACTS

Attempts:

3 left

💡 Hint

Common Mistakes

Using different permissions in check and request.

Forgetting to wrap the permission in an array when requesting.

Both blanks require Manifest.permission.CAMERA to check and request the camera permission.

5fill in blank

hard

Fill all three blanks to handle permission result and show a message if permission is denied.

Android Kotlin

override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults)
    if (requestCode == REQUEST_CAMERA_CODE) {
        if (grantResults.isNotEmpty() && grantResults[[1]] == PackageManager.PERMISSION_GRANTED) {
            Toast.makeText(this, [2], Toast.LENGTH_SHORT).show()
        } else {
            Toast.makeText(this, [3], Toast.LENGTH_SHORT).show()
        }
    }
}

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

A0

B"Camera permission granted"

C"Camera permission denied"

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong index for grantResults.

Mixing up granted and denied messages.

Forgetting to call super method.

Index 0 checks the first permission result. Show a granted message if permission is allowed, else show denied message.

Practice

1. What is the first step before requesting a dangerous permission in Android Kotlin?

easy

A. Restart the app

B. Directly call requestPermissions without checking

C. Show a Toast message to the user

D. Check if the permission is already granted

Solution

1. Step 1: Understand permission checking

   Before asking for permission, the app must check if it already has it to avoid unnecessary requests.

2. Step 2: Use ContextCompat.checkSelfPermission

   This method returns if the permission is granted or denied, guiding the next action.

3. Final Answer:

   Check if the permission is already granted -> Option D

4. Quick Check:

   Check permission first = A [OK]

Hint: Always check permission status before requesting [OK]

Common Mistakes:

• Requesting permission without checking first
• Assuming permission is granted by default
• Ignoring permission status before action

2. Which Kotlin code snippet correctly requests a permission from an Activity?

easy

A. ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.CAMERA), 100)

B. requestPermissions(Manifest.permission.CAMERA, 100)

C. Activity.requestPermissions(this, Manifest.permission.CAMERA, 100)

D. requestPermission(Manifest.permission.CAMERA)

Solution

1. Step 1: Identify correct method signature

   ActivityCompat.requestPermissions requires context, array of permissions, and request code.

2. Step 2: Check syntax correctness

   ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.CAMERA), 100) matches the correct syntax with 'this' as context and arrayOf for permissions.

3. Final Answer:

   ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.CAMERA), 100) -> Option A

4. Quick Check:

   Correct requestPermissions syntax = D [OK]

Hint: Use ActivityCompat.requestPermissions with arrayOf permissions [OK]

Common Mistakes:

• Passing single permission string instead of array
• Using wrong method name or class
• Missing context parameter

3. Given this code snippet inside an Activity:

override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
  super.onRequestPermissionsResult(requestCode, permissions, grantResults)
  if (requestCode == 101 && grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
    println("Permission granted")
  } else {
    println("Permission denied")
  }
}

What will be printed if the user denies the permission?

medium

A. Permission denied

B. Permission granted

C. No output

D. App crashes

Solution

1. Step 1: Analyze grantResults array

   If the user denies permission, grantResults[0] will not equal PERMISSION_GRANTED.

2. Step 2: Follow conditional logic

   The else branch executes, printing "Permission denied".

3. Final Answer:

   Permission denied -> Option A

4. Quick Check:

   User denies permission = "Permission denied" [OK]

Hint: Denied permission triggers else branch in onRequestPermissionsResult [OK]

Common Mistakes:

• Assuming grantResults[0] is always granted
• Not checking if grantResults is empty
• Ignoring requestCode check

4. What is wrong with this permission request code snippet?

ActivityCompat.requestPermissions(this, Manifest.permission.ACCESS_FINE_LOCATION, 200)

medium

A. Request code 200 is invalid

B. Missing arrayOf() around permission string

C. Should use ContextCompat instead of ActivityCompat

D. No need to request ACCESS_FINE_LOCATION permission

Solution

1. Step 1: Check method parameters

   requestPermissions expects an array of permissions, not a single string.

2. Step 2: Identify correct usage

   Permission string must be wrapped in arrayOf() to form an array.

3. Final Answer:

   Missing arrayOf() around permission string -> Option B

4. Quick Check:

   Permissions must be in arrayOf() [OK]

Hint: Wrap permissions in arrayOf() when requesting [OK]

Common Mistakes:

• Passing single permission string instead of array
• Confusing ContextCompat with ActivityCompat
• Using invalid request codes

5. You want to request both CAMERA and LOCATION permissions at once. Which code correctly handles the request and checks the result in Kotlin?

hard

A. requestPermissions(arrayOf(Manifest.permission.CAMERA, Manifest.permission.ACCESS_FINE_LOCATION), 300)
override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
println("Permissions handled")
}

B. ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.CAMERA), 300)
override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
if (requestCode == 300 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
println("All permissions granted")
} else {
println("Some permissions denied")
}
}

C. ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.CAMERA, Manifest.permission.ACCESS_FINE_LOCATION), 300)
override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
if (requestCode == 300 && grantResults.all { it == PackageManager.PERMISSION_GRANTED }) {
println("All permissions granted")
} else {
println("Some permissions denied")
}
}

D. ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.CAMERA, Manifest.permission.ACCESS_FINE_LOCATION), 300)
override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
if (requestCode == 300 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
println("All permissions granted")
} else {
println("Some permissions denied")
}
}

Solution

1. Step 1: Request multiple permissions correctly

   Use arrayOf with both permissions and a unique request code.

2. Step 2: Check all permissions granted in onRequestPermissionsResult

   Use grantResults.all { it == PackageManager.PERMISSION_GRANTED } to verify all permissions.

3. Final Answer:

   Request both permissions and check all granted with grantResults.all -> Option C

4. Quick Check:

   Multiple permissions need all granted check [OK]

Hint: Check all grantResults for multiple permissions [OK]

Common Mistakes:

• Checking only first permission result
• Not using arrayOf for multiple permissions
• Ignoring requestCode in result handler