Forwarded from Android books channel🤖
What is the name of the architectural style that separates responsibilities into models, views, and controllers?
Anonymous Quiz
1%
REST
6%
MVP (Model-View-Presenter)
12%
MVVM (Model-View-ViewModel)
81%
MVC (Model-View-Controller)
Which architectural pattern is best suited for an Android application to separate logic, UI, and data management?
Anonymous Quiz
10%
MVC
6%
MVP
80%
MVVM
4%
Singleton
Which Android component is responsible for managing the lifecycle of an activity?
Anonymous Quiz
29%
ActivityManager
35%
LifecycleOwner
32%
Activity
3%
Application
Which mechanism in Android is used for data exchange between application components?
Anonymous Quiz
58%
Intent
8%
SharedPreferences
25%
ContentProvider
8%
BroadcastReceiver
Forwarded from Android books channel🤖
How can you update the state in Jetpack Compose when data changes?
Anonymous Quiz
10%
Use setState() to update the state.
43%
Wrap the state variable in remember { mutableStateOf() } and modify its value directly.
41%
Use reactive data source like LiveData or StateFlow and subscribe to changes using collectAsState()
6%
Use updateState() to update the component's state.
Forwarded from Android books channel🤖
Which method is typically overridden in a ViewModel to perform cleanup operations when it is no longer needed?
Anonymous Quiz
22%
onDestroy()
21%
OnClear()
42%
onCleared()
8%
onDestroyed()
7%
OnCleared()
Forwarded from Android books channel🤖
Which method of the android.widget.SimpleAdapter class is used to set data and layout for binding data with a view in Android applications?
Anonymous Quiz
16%
setDataSource()
26%
bindLayout()
29%
setAdapterData()
29%
setViewBinder()
Forwarded from Android books channel🤖
What are the layers of clean architecture (Fernando Cejas)?
Anonymous Quiz
14%
View, Domain, Repository
74%
Presentation, Domain, Data
4%
View, Data
8%
Core, Domain, Data
Forwarded from Android books channel🤖
What callbacks and in what sequence are called when the screen is rotated?
Anonymous Quiz
22%
onPause, onStop, onSaveInstanceState, onDestroy–onCreate, onStart, onRestoreInstanceState, onResume
10%
onPause, onSaveInstanceState, onDestroy–onCreate, onStart, onRestoreInstanceState, onResume
41%
onPause, onStop, onSaveInstanceState, onDestroy–onCreate, onRestoreInstanceState, onStart, onResume
27%
onPause, onSaveInstanceState, onStop, onDestroy–onCreate, onRestoreInstanceState, onStart, onResume
Forwarded from Android books channel🤖
FragmentManager.commit() method - synchronous or asynchronous?
Anonymous Quiz
49%
Synchronous
51%
Asynchronous
Which Android component is used for executing background tasks without a user interface?
Anonymous Quiz
3%
Activity
11%
BroadcastReceiver
84%
Service
2%
ContentProvider
🤩1
Question and answer
What is the difference between an abstract class and an interface in Java?
Answer:An abstract class is a class that cannot be instantiated, and it can have abstract and non-abstract methods. An interface, on the other hand, is a collection of abstract methods and constants that can be implemented by any class. One key difference between the two is that a class can implement multiple interfaces, but it can only extend one abstract class .
#question #answer #java
What is the difference between an abstract class and an interface in Java?
Answer:
#question #answer #java
Question and answer
What is the difference between the “==” operator and the “.equals()” method in Java?
Answer:The “==” operator checks for object reference equality, while the “.equals()” method checks for object value equality. For example, two different String objects with the same value will return true when compared using “.equals()”, but false when compared using “==”.
#question #answer #java
What is the difference between the “==” operator and the “.equals()” method in Java?
Answer:
#question #answer #java
👍1
Java and Kotlin
1. What is the difference between an abstract class and an interface in Java?
Answer:An abstract class is a class that cannot be instantiated, and it can have abstract and non-abstract methods. An interface, on the other hand, is a collection of abstract methods and constants that can be implemented by any class. One key difference between the two is that a class can implement multiple interfaces, but it can only extend one abstract class.
2. What is the difference between the “==” operator and the “.equals()” method in Java?
Answer:The “==” operator checks for object reference equality, while the “.equals()” method checks for object value equality. For example, two different String objects with the same value will return true when compared using “.equals()”, but false when compared using “==”.
3. What is a lambda expression in Kotlin?
Answer:A lambda expression is a way to define a function in Kotlin without creating a separate named function. It allows you to define a function inline, using a more concise syntax. For example, the following code defines a lambda expression that takes two integers and returns their sum: “(x: Int, y: Int) -> x + y”.
4. What is the difference between a lateinit property and an initialized property in Kotlin?
Answer:A lateinit property is a property that is declared without an initial value, but is guaranteed to be initialized before it is used. This is useful for properties that cannot be initialized in the constructor, but need to be initialized before they are used. An initialized property, on the other hand, is a property that is declared with an initial value and can be used immediately.
5. What is the difference between a HashSet and a TreeSet in Java?
Answer:A HashSet is an unordered set of unique elements, implemented using a hash table. A TreeSet, on the other hand, is an ordered set of unique elements, implemented using a red-black tree. The elements in a TreeSet are stored in sorted order.
6. What is a companion object in Kotlin?
Answer:A companion object is an object that is associated with a class, rather than an instance of the class. It can be used to define static methods and properties for the class. For example, the following code defines a companion object for the MyClass class, with a static method “myStaticMethod”:
class MyClass {
companion object {
fun myStaticMethod() {
/* code */ }
}
}
7. What is the difference between a class and an object in Kotlin?
Answer:A class is a blueprint for creating objects, while an object is a single instance of a class. Objects are often used to implement singletons in Kotlin.
8. What is polymorphism in Java?
Answer:Polymorphism is the ability of an object to take on multiple forms. In Java, this can be achieved through inheritance and method overriding. For example, a subclass can override a method from its superclass to provide a different implementation.
9. What is a functional interface in Java?
Answer:A functional interface is an interface that has only one abstract method. It is often used with lambda expressions and method references in Java. Java provides the @FunctionalInterface annotation to indicate that an interface is a functional interface.
10. What is the difference between a private and a protected method in Java?
Answer:A private method is a method that can only be accessed within the same class. A protected method, on the other hand, can be accessed within the same class and any subclasses.
#QuestionsAndAnswers #java #kotlin #JavaKotlin
1. What is the difference between an abstract class and an interface in Java?
Answer:
2. What is the difference between the “==” operator and the “.equals()” method in Java?
Answer:
3. What is a lambda expression in Kotlin?
Answer:
4. What is the difference between a lateinit property and an initialized property in Kotlin?
Answer:
5. What is the difference between a HashSet and a TreeSet in Java?
Answer:
6. What is a companion object in Kotlin?
Answer:
class MyClass {
companion object {
fun myStaticMethod() {
/* code */ }
}
}
7. What is the difference between a class and an object in Kotlin?
Answer:
8. What is polymorphism in Java?
Answer:
9. What is a functional interface in Java?
Answer:
10. What is the difference between a private and a protected method in Java?
Answer:
#QuestionsAndAnswers #java #kotlin #JavaKotlin
Android Components
1. What are the key Android app components?
Answer:The key Android app components are Activities, Fragments, Services, Broadcast Receivers, and Content Providers.
2. What is an Activity in Android?
Answer: An Activity represents a single screen with a user interface that is used to interact with the app. It manages the UI components and receives and handles user input.
3. What is a Fragment in Android?
Answer:A Fragment is a reusable UI component that represents a part of an Activity. It can be used to build multi-pane UIs and can be added or removed dynamically during runtime.
4. What is a Service in Android?
Answer:A Service is a background process that performs long-running tasks without a user interface. It can run in the background even if the app is not in the foreground.
5. What is a Broadcast Receiver in Android?
Answer:A Broadcast Receiver is a component that listens for system or app events and performs tasks based on those events. It is used to receive and respond to broadcast messages from other components or system events.
6. What is a Content Provider in Android?
Answer:A Content Provider is a component that manages a shared set of app data that can be accessed by other apps or components. It provides a standardized interface to access and manipulate data.
7. What is the lifecycle of an Activity in Android?
Answer:The lifecycle of an Activity in Android includes several states, such as Created, Started, Resumed, Paused, Stopped, and Destroyed. Each state has specific methods that can be overridden to perform actions during that state.
8. How do you pass data between Activities in Android?
Answer:Data can be passed between Activities in Android by using Intent extras or by using the startActivityForResult method.
9. What is the purpose of a Bundle in Android?
Answer:A Bundle is a container for data that can be passed between components in Android, such as Activities, Fragments, or Services. It is often used to save and restore instance state data.
10. What is the difference between a Service and an IntentService in Android?
Answer:A Service is a background process that runs continuously until it is stopped, whereas an IntentService is a subclass of Service that runs for a short period of time to perform a single task and then stops itself automatically. An IntentService can be used for background tasks that need to be performed in a separate thread.
#QuestionsAndAnswers #AndroidComponents
1. What are the key Android app components?
Answer:
2. What is an Activity in Android?
Answer:
3. What is a Fragment in Android?
Answer:
4. What is a Service in Android?
Answer:
5. What is a Broadcast Receiver in Android?
Answer:
6. What is a Content Provider in Android?
Answer:
7. What is the lifecycle of an Activity in Android?
Answer:
8. How do you pass data between Activities in Android?
Answer:
9. What is the purpose of a Bundle in Android?
Answer:
10. What is the difference between a Service and an IntentService in Android?
Answer:
#QuestionsAndAnswers #AndroidComponents