Why platform APIs access device capabilities in iOS Swift - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the framework that allows access to device features.

iOS Swift

import [1]

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

AFoundation

BUIKit

CCoreData

DAVFoundation

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing Foundation which is for basic data types and collections.

Choosing CoreData which is for data storage.

Choosing AVFoundation which is for audio and video.

The UIKit framework provides the necessary APIs to access many device capabilities like the screen, touch, and sensors.

2fill in blank

medium

Complete the code to request permission to use the device camera.

iOS Swift

AVCaptureDevice.requestAccess(for: .video) { granted in
    if [1] {
        print("Camera access granted")
    } else {
        print("Camera access denied")
    }
}

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

Agranted

Bpermission

Caccess

Dallowed

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name not defined in the closure parameter.

Confusing the parameter with a permission object.

The closure parameter 'granted' is a Boolean indicating if the user allowed camera access.

3fill in blank

hard

Fix the error in the code to get the current device orientation.

iOS Swift

let orientation = UIDevice.current.[1]

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

Aorientation

BdeviceOrientation

CcurrentOrientation

DorientationState

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect property names that do not exist.

Trying to access orientation from the wrong object.

The correct property to get the device's orientation is 'orientation' on UIDevice.current.

4fill in blank

hard

Fill both blanks to create a dictionary that maps sensor names to their availability status.

iOS Swift

let sensors = ["Accelerometer": [1], "Gyroscope": [2]]

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ACMMotionManager().isAccelerometerAvailable

BCMMotionManager().isGyroAvailable

CCMMotionManager().isMagnetometerAvailable

DCMMotionManager().isDeviceMotionAvailable

Attempts:

3 left

💡 Hint

Common Mistakes

Using properties for other sensors like magnetometer or device motion.

Mixing up the property names.

CMMotionManager provides properties to check if accelerometer and gyroscope sensors are available on the device.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that filters sensors available on the device.

iOS Swift

let availableSensors = [
    [1]: [2] for [3] in ["Accelerometer", "Gyroscope", "Magnetometer"]
    if CMMotionManager().is[1]Available
]

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

Asensor

Btrue

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'false' as value which would be incorrect for available sensors.

Using different variable names inconsistently.

This code creates a dictionary with sensor names as keys and 'true' as values only if the sensor is available.