Creating a new Android project in Android Kotlin - Practice Exercises

Challenge - 5 Problems

❓ ui_behavior

intermediate

What is the default launcher activity in a new Android project?

When you create a new Android project in Android Studio with the default settings, which activity is set as the launcher activity that opens first when the app starts?

A HomeActivity

B SplashActivity

C MainActivity

D LoginActivity

💡 Hint

Think about the activity Android Studio creates automatically for you.

The default activity created by Android Studio in a new project is named MainActivity and it is set as the launcher activity in the manifest.

❓ lifecycle

intermediate

What lifecycle method is called first when the app starts?

In the default MainActivity of a new Android project, which lifecycle method is called first when the app is launched?

A onCreate()

B onStart()

C onResume()

D onDestroy()

💡 Hint

This method is where you usually set your layout.

The onCreate() method is the first lifecycle callback called when the activity is created and is where you initialize your UI.

📝 Syntax

advanced

Which Kotlin code snippet correctly sets the content view in MainActivity?

In the MainActivity.kt file of a new Android project, which code correctly sets the layout resource named activity_main as the content view?

Android Kotlin

class MainActivity : AppCompatActivity() {
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    // Set content view here
  }
}

A setContentView("activity_main")

B setContentView(R.layout.activity_main)

C setContentView(R.id.activity_main)

D setContentView(layout.activity_main)

💡 Hint

The layout resource is accessed via R.layout.

The correct way to set the layout is using setContentView(R.layout.activity_main). Using R.id or strings will cause errors.

❓ navigation

advanced

What happens if you forget to declare MainActivity in AndroidManifest.xml?

If you create MainActivity.kt but do not add it to AndroidManifest.xml, what will happen when you try to run the app?

A The app crashes with ActivityNotFoundException at startup

B The app runs but shows a blank screen

C The app runs normally without issues

D The app shows a compile-time error

💡 Hint

Android needs to know which activity to launch first.

If MainActivity is not declared in the manifest, the system cannot find the launcher activity and throws ActivityNotFoundException at runtime.

🧠 Conceptual

expert

Why does Android Studio create a Gradle build file in a new project?

When you create a new Android project, Android Studio generates build.gradle files. What is the main purpose of these Gradle files?

A To define AndroidManifest.xml contents

B To store user interface layouts

C To write Kotlin code for activities

D To manage project dependencies and build configurations

💡 Hint

Think about how the app knows which libraries to include and how to compile.

Gradle build files tell Android Studio how to compile the app and which libraries to include, managing dependencies and build settings.