Important Interview Questions for Android 

Q 11: What is the difference between Serializable and Parcelable ? 

Ans: Serializable is a standard Java interface. You mark a class Serializable by implementing the interface, and Java will automatically serialize it in certain situations.
Parcelable is an Android-specific interface for serialization. It has been designed to be much more efficient and to deal with some of the Java serialization default issues.

Q 12: What database is used in Android? How is it different from client-server database management systems?

Ans: SQLite is the relational open-source database for Android applications. The server free, transactional and self-contained SQLite engine is also available. The SQLite engine is integrated with the application rather than the client-server connection of the majority of data base management solutions. The library may be dynamically invoked, and simple function calls that minimise data access latency can be applied.

Q 13: What is the significance of the .dex file?

Ans: In a Dalvik Executer file, Android applications must be compiled by DVM into a.dex file and then zipded into a. apk. . Dex files are produced using Java-written translations of built programmes. . dex is an optimised format for efficient storing and storage operations.

Q 14: Explain Sensors in Android.

Ans: Android-based gadgets feature a number of integrated sensors, which detect several characteristics such as movement, focus and much more by their great precision. Both hardware and nature-based software might be the sensors. There are three main categories of sensors in Android devices. They are:

Position Sensor: It is used for measuring the physical position of the Android device. This has orientation sensors and magnetometers.

Motion Sensors: These sensors consist of gravity, rotational activity, and acceleration sensors which measure the rotation of the device or the acceleration, etc.

Environmental Sensor: It includes sensors that measure temperature, humidity, pressure, and other environmental factors.

Q 15: What is a broadcast receiver?

Ans: The broadcast receiver communicates with the operating system messages such as "check whether an internet connection is available," what the battery label should be, etc.