Camera access (expo-camera) in React Native - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the expo-camera library in React Native?

The expo-camera library allows React Native apps to access and use the device's camera for taking photos and recording videos.

beginner

How do you request permission to use the camera with expo-camera?

You use the Camera.requestCameraPermissionsAsync() method to ask the user for permission to access the camera.

beginner

What React hook is commonly used to manage camera permission state in a functional component?

The useState hook is used to store and update the camera permission status (granted or denied).

intermediate

Why should you check camera permissions before rendering the camera view?

Checking permissions first ensures the app only tries to show the camera if the user has allowed access, preventing errors and improving user experience.

beginner

How do you display the camera preview on screen using expo-camera?

You render the <Camera> component from expo-camera and set its style and type (front or back camera).

Which method requests camera permission in expo-camera?

A Camera.getPermissions()

B Permissions.askCamera()

C Camera.requestCameraPermissionsAsync()

D Camera.enable()

The correct method to request camera permission is Camera.requestCameraPermissionsAsync().

What React hook is best to track if camera permission is granted?

A useState

B useContext

C useRef

D useEffect

The useState hook is used to store and update permission status.

Which component shows the live camera feed in expo-camera?

A <Camera>

B <CameraFeed>

C <CameraView>

D <CameraPreview>

The <Camera> component displays the live camera preview.

What should you do if camera permission is denied?

A Force camera to open anyway

B Show an error message or alternative UI

C Restart the app

D Ignore and continue

If permission is denied, show a message or alternative UI to inform the user.

Which camera type can you select in expo-camera?

A Only front camera

B No camera selection possible

C Only back camera

D Front or back camera

You can choose between front and back cameras using the type prop.

Explain how to request and handle camera permissions using expo-camera in a React Native app.

Think about asking the user first, then showing the camera only if allowed.

Describe how to display a live camera preview using the expo-camera library.

Focus on the component and props needed for the preview.