25 Mobile App Developer Interview Questions and Answers CLIMB

It also disables screen compatibility mode when running on larger screens . The targetSdkVersion indicates that you have tested your app on the version you specify. This is like a certification or sign-off you are giving the Android OS as a hint to how it should handle your application in terms of OS features. The compileSdkVersion is the version of API the application is compiled against. You can use Android API features involved in that version of the API . ‘OK, Google’ feature allows access to Google to the users without touching your smartphones. An application should perform lengthy database or networking operations in separate threads to avoid ANR.

Simulate realistic interviews for over 120 job different titles, with curated questions from real employers. These questions are used by companies around the world in their interviews. Not questions «like these» or «based on these» – companies literally use these exact questions.

What is JobScheduler?

Portable Wi-Fi Hotspot permits you to share your mobile internet connection with other wireless devices. For example, using your Android phone as a Wi-Fi hotspot, you can use your laptop to connect to the internet using that access point. On the other hand, services are designed to run in the background, and they can act independently. Service is an application component that facilitates an application to run in the background in order to perform long-running operations without user interaction.

One technique that prevents the Android system from concluding a code that has been responsive for a long period of time is to create a child thread. Within the child thread, most of the actual workings of the codes can be placed, so that the main thread runs with minimal periods of unresponsive times. This is actually a dialog that appears to the user whenever an application have been unresponsive for a long period of time.

What is meant by QOS in app development?

Since iOS 6 we have AutoLayout, which is the go-to solution these days and which Apple prefers. AutoLayout is a technology that helps you define relationships between views, called constraints, in a declarative way, letting the framework calculate precise frames and positions of UI elements instead. In-memory arrays, dictionaries, sets, and other data structures are perfectly fine for storing data intermediately or if it doesn’t have to be persisted. The Dependency Inversion Principle states, “depend on abstractions, not concretions.” The best example that showcases this principle is the Dependency Injection technique. Another malicious side effect of “convenient” singletons is the global state. Often singletons enable global state sharing and play the role of a “public bag” that every object uses to store state. That leads to unpredictable results and bugs or crashes when this uncontrolled state gets overridden or removed by someone.

• When designing menus used by applications native to a computing platform or web browser, the developer has a great deal of latitude due to the user interface’s size and flexibility.
• This not only saves time and money, but also allows for a consistent user experience across devices.
• If they seem friendly and collaborative, emphasize that you enjoy working in those types of environments.
• SRP starts with small concrete and specific cases such as a class and/or an object having only one purpose and being used only for only one thing.
• These possibilities can happen even to the most careful recruiter.
• ” Or, inquire if there are active mobile apps currently available in the App Store or Google Play that the applicant has worked on.
• Most likely every single interviewer will ask about this regardless whether you’re applying for a senior or junior position.

A reference to the instance is stored, and the same is shared with anyone who retained it. At the same time, copy means that the object will be cloned with duplicated value, but it cannot be shared with anyone else.

What is the difference between Serializable and Parcelable? Which is the best approach in Android?

This process involves breaking down objects into primitives that Android can understand. This part is required simply because a process cannot access the memory of the other process.

These alternatives are good in certain scenarios when, for example, you need to build highly dynamic and fast table views and collection views. AutoLayout is not always perfect for that and knowing there are other options is always good. The main red flag here is not being aware that these data manipulations need to happen when working with the networking and storage layers of your iOS applications. Things do not happen “automagically”, nor is working with raw NSDictionaries appropriate and maintainable. Interviewers ask this question to grasp your understanding of what tools and ways you have available to store and persist data on iOS.

An how to become a mobile developerd developer may still be capable of learning the functionality building you need; speak with them one-on-one to learn more. The best way to learn about a potential candidate is to learn from the past.