Cognizant Android Developer Interview Questions and Answers

Coroutines are a way to perform asynchronous operations in Android, securing app data involves encryption, SSL pinning enhances security, FCM for notifications.

• Coroutines are used for managing asynchronous operations in Android, allowing for efficient and non-blocking code execution.

• Securing app data involves using encryption techniques such as AES to protect sensitive information from unauthorized access.

• SSL pinning is a security measure that ensures the app only communicate...read more

A singleton class is a class that can only have one instance created at a time. Proguard is a tool used for code obfuscation and optimization. ViewModel is a class that stores and manages UI-related data.

• To create a singleton class, make the constructor private, create a static method to return the instance, and use a static variable to hold the instance.

• Proguard is used to shrink, optimize, and obfuscate the code in an Android application to make it smaller and more efficien...read more

commit() writes the changes synchronously, apply() writes the changes asynchronously.

• commit() returns a boolean value indicating success or failure, while apply() does not.

• commit() writes the changes immediately to the disk, while apply() writes the changes to the memory first and then to the disk asynchronously.

• apply() is faster than commit() as it writes the changes in the background thread.

• Use commit() when you need to read the preference immediately after writing, use app...read more

Yes, users can downgrade an app from PlayStore by uninstalling the current version and installing an older version manually.

• Users can uninstall the current version of the app from their device.

• They can then search for the older version of the app APK file online or use a backup they may have.

• After downloading the older version APK, they can manually install it on their device.

Yes, we can use Activity without XML by programmatically creating the UI elements.

• Activities can be created and managed entirely in code without using XML layouts.

• UI elements can be added to the activity using Java code.

• This approach is useful for creating dynamic UIs or for cases where XML layouts are not suitable.

Alpha testing is done by internal teams before release, while beta testing is done by external users after alpha testing.

• Alpha testing is done by internal teams to identify bugs and issues before releasing the software to the public.

• Beta testing is done by external users who are not part of the development team to gather feedback and identify any remaining issues.

• Alpha testing is usually done in a controlled environment, while beta testing is done in a real-world setting.

• Alph...read more