Hoffensoft Interview Questions and Answers

The app life cycle in iOS refers to the sequence of events that occur from the time an app is launched to when it is terminated.

• The app is launched by the user or system.

• The app enters the foreground and becomes active.

• The app can enter the background when the user switches to another app or the device locks.

• The app can be terminated by the user or system.

• The app can also be suspended, where it remains in memory but do...read more

Classes are reference types, while structs are value types in Swift.

• Classes are reference types, meaning they are passed by reference. Changes made to one instance will affect all references to that instance.

• Structs are value types, meaning they are passed by value. Each instance has its own copy, so changes made to one instance do not affect others.

• Classes support inheritance, while structs do not.

• Classes have deiniti...read more

Protocol is a set of methods and properties that a class, struct, or enum can implement to define a particular functionality.

• Protocols define a blueprint of methods, properties, and other requirements that a class or struct must adhere to.

• They are similar to interfaces in other programming languages.

• Classes, structs, and enums can adopt protocols by conforming to them.

• Protocols allow for polymorphism and code reuse in ...read more

Types of access controls in iOS include public, internal, private, and fileprivate.

• Public: Accessible from anywhere, both within the module and outside.

• Internal: Accessible from anywhere within the module.

• Private: Accessible only within the defining type.

• Fileprivate: Accessible only within the same file.

A closure is a self-contained block of code that can be passed around and used in your code.

• Closures capture and store references to any constants and variables from the context in which they are defined.

• Closures are similar to blocks in Objective-C and lambdas in other programming languages.

• Closures can be used to pass functions as arguments to other functions.

• Example: { (parameters) -> return type in code }

Generics allow you to write flexible, reusable functions and data types that can work with any type.

• Generics enable you to write functions and data types that can work with any type.

• They help in writing flexible and reusable code.

• Example: Array can hold elements of any type T.

APNs life cycle refers to the process of sending push notifications to iOS devices.

• APNs connects with the device through a persistent and secure connection.

• The device registers with APNs to receive push notifications.

• When a push notification is sent, APNs delivers it to the device.

• If the device is offline, APNs stores the notification and delivers it when the device is back online.

Intent is a messaging object used to request an action from another app component. There are two types of intents: explicit and implicit.

• Intent is used to start an activity, service, or broadcast receiver.

• Explicit intent specifies the component to be invoked by its name.

• Implicit intent specifies the action to be performed and optionally, the data to be used.

• Examples of implicit intents are opening a webpage or making a...read more

Activity and Fragment life cycles are a series of states that an Android component goes through during its lifetime.

• Activity life cycle includes onCreate(), onStart(), onResume(), onPause(), onStop(), and onDestroy() methods.

• Fragment life cycle includes onAttach(), onCreate(), onCreateView(), onActivityCreated(), onStart(), onResume(), onPause(), onStop(), onDestroyView(), and onDetach() methods.

• Both life cycles are im...read more

Activity is a single screen with a user interface, while fragments are a portion of the user interface in an activity.

• Activity is a standalone component that can be launched by an application.

• Fragments are reusable components that can be used in multiple activities.

• An activity can contain multiple fragments.

• Fragments have their own lifecycle and can be added or removed dynamically.

• Example: A music player app can have a...read more

ArrayList is a resizable array while HashMap is a key-value pair collection.

• ArrayList is ordered while HashMap is unordered

• ArrayList allows duplicate values while HashMap does not

• HashMap provides faster access to elements using keys

• Use ArrayList when you need to maintain the order of elements

• Use HashMap when you need to access elements using keys

Firebase Notification is a cloud messaging service provided by Google.

• Firebase Notification allows developers to send messages and notifications to their app users.

• It supports both Android and iOS platforms.

• It provides a console to send notifications to specific devices or topics.

• It also supports sending notifications based on user behavior and location.

• Firebase Notification can be integrated with other Firebase servic...read more

Java is a high-level, object-oriented programming language used for developing desktop, web, and mobile applications.

• Java is platform-independent and can run on any operating system.

• It is statically typed, meaning that variables must be declared before use.

• Java is used for developing Android applications, enterprise applications, and web applications.

• It is known for its security features, such as the Java Security Mana...read more

Oops concept in java

• Object-oriented programming paradigm

• Encapsulation, Inheritance, Polymorphism, Abstraction

• Classes and Objects

• Access Modifiers

• Interfaces and Abstract Classes

SDK stands for Software Development Kit. It is a set of tools and resources used for developing applications for a specific platform.

• SDK provides developers with APIs, libraries, and documentation to build applications for a specific platform.

• Android SDK includes tools like Android Studio, ADB, and Emulator.

• SDK helps developers to test, debug, and optimize their applications.

• SDK also provides sample code and templates ...read more

Retrofit and Volley are popular networking libraries for Android development.

• Retrofit is a type-safe HTTP client for Android and Java.

• Volley is a fast and efficient networking library for Android.

• Retrofit uses annotations to define API endpoints and request parameters.

• Volley provides easy-to-use APIs for making network requests and handling responses.

• Retrofit is best suited for RESTful APIs, while Volley is more versat...read more

Modules are independent units of code that can be used to build larger software systems.

• Modules can be reused in different projects

• They can be developed and tested independently

• Modules can be combined to form a larger system

• Examples include libraries, plugins, and frameworks

Signed APK is a single file that is signed and ready for distribution, while bundle is a publishing format that includes multiple APKs optimized for different device configurations.

• Signed APK is generated from a single APK file, while bundle generates multiple APKs.

• Signed APK is signed with a private key, while bundle is signed with an upload key.

• Bundle includes multiple APKs optimized for different device configuratio...read more