Creating a new Android project in Android Kotlin - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a new Android Activity class named MainActivity.

Android Kotlin

class MainActivity : [1]() {
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)
  }
}

Drag options to blanks, or click blank then click option'

AFragmentActivity

BActivityMain

CAppCompatActivity

DViewModel

Attempts:

3 left

💡 Hint

Common Mistakes

Using ActivityMain instead of AppCompatActivity

Extending ViewModel which is not an Activity

Using FragmentActivity which is for fragments

The MainActivity class should extend AppCompatActivity to work properly as an Android activity.

2fill in blank

medium

Complete the code to set the layout resource for the activity in onCreate.

Android Kotlin

override fun onCreate(savedInstanceState: Bundle?) {
  super.onCreate(savedInstanceState)
  [1](R.layout.activity_main)
}

Drag options to blanks, or click blank then click option'

AsetContentView

Binflate

CsetLayout

DloadLayout

Attempts:

3 left

💡 Hint

Common Mistakes

Using inflate which is for view binding

Using setLayout or loadLayout which do not exist

The method setContentView sets the UI layout for the activity.

3fill in blank

hard

Fix the error in the import statement to use the correct Android package for Bundle.

Android Kotlin

import [1].os.Bundle

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Aandroidx

Bandroid

Ckotlin

Djava

Attempts:

3 left

💡 Hint

Common Mistakes

Using androidx.os.Bundle which does not exist

Using kotlin.os.Bundle which is invalid

The correct package for Bundle is android.os.Bundle.

4fill in blank

hard

Fill both blanks to declare a new Android project package and main activity class header.

Android Kotlin

package [1]

class MainActivity : [2]()

Drag options to blanks, or click blank then click option'

Acom.example.myapp

BAppCompatActivity

Candroid.app

DMainActivity

Attempts:

3 left

💡 Hint

Common Mistakes

Using android.app as package name

Using MainActivity as a base class

The package name should be your app's unique identifier like com.example.myapp. The activity class should extend AppCompatActivity.

5fill in blank

hard

Fill all three blanks to complete the minimal MainActivity code with onCreate method and layout setting.

Android Kotlin

package [1]

import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity

class MainActivity : [2]() {
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    [3](R.layout.activity_main)
  }
}

Drag options to blanks, or click blank then click option'

Acom.example.app

BAppCompatActivity

CsetContentView

Dandroid.app

Attempts:

3 left

💡 Hint

Common Mistakes

Using android.app as package name

Forgetting to extend AppCompatActivity

Using inflate instead of setContentView

The package name is usually your app's domain reversed like com.example.app. The activity extends AppCompatActivity. The layout is set with setContentView.

Practice

1. What is the first step when creating a new Android project in Android Studio?

easy

A. Create a new Java file manually

B. Write Kotlin code directly without any setup

C. Download an app from the Play Store

D. Open Android Studio and select 'New Project' from the welcome screen

Solution

1. Step 1: Open Android Studio

   You start by launching Android Studio, the official tool for Android development.

2. Step 2: Select 'New Project'

   From the welcome screen, you choose 'New Project' to begin setting up your app.

3. Final Answer:

   Open Android Studio and select 'New Project' from the welcome screen -> Option D

4. Quick Check:

   First step = Open Android Studio and start new project [OK]

Hint: Always start by opening Android Studio and choosing 'New Project' [OK]

Common Mistakes:

• Trying to write code before creating a project
• Skipping Android Studio and using other tools
• Downloading apps instead of creating one

2. Which language should you select when creating a new Android project to use Kotlin?

easy

A. Kotlin

B. Java

C. C++

D. Python

Solution

1. Step 1: Choose the programming language option

   During project setup, Android Studio asks which language to use for your app.

2. Step 2: Select Kotlin for modern Android development

   Kotlin is the recommended language for Android apps, so you pick Kotlin here.

3. Final Answer:

   Kotlin -> Option A

4. Quick Check:

   Language choice = Kotlin [OK]

Hint: Pick Kotlin language option to write Android apps [OK]

Common Mistakes:

• Choosing Java instead of Kotlin
• Selecting unsupported languages like Python
• Not selecting any language

3. After creating a new Android project with an Empty Activity template, what will the default screen show when you run the app?

medium

A. A screen showing a list of items

B. A screen showing 'Hello World!' text with no buttons

C. A screen with a button labeled 'Click Me'

D. An error message saying 'No layout found'

Solution

1. Step 1: Understand the Empty Activity template

   This template creates a simple app with minimal UI: a single TextView displaying 'Hello World!' by default.

2. Step 2: Run the app to see the default UI

   When you run the app, it shows 'Hello World!' text on screen with no buttons.

3. Final Answer:

   A screen showing 'Hello World!' text with no buttons -> Option B

4. Quick Check:

   Empty Activity default UI = 'Hello World!' screen [OK]

Hint: Empty Activity shows 'Hello World!' text initially [OK]

Common Mistakes:

• Expecting buttons or lists by default
• Thinking the app shows a list automatically
• Confusing error messages with default UI

4. You created a new Android project but the app crashes on launch with an 'ActivityNotFoundException'. What is the most likely cause?

medium

A. You forgot to select Kotlin as the language during project creation

B. You did not connect a physical device

C. You did not set a launcher activity in the manifest

D. You used an unsupported Android Studio version

Solution

1. Step 1: Understand the error meaning

   'ActivityNotFoundException' often means the app can't find the starting point (launcher activity).

2. Step 2: Check AndroidManifest.xml for launcher activity

   If no launcher activity is set, the app crashes because it doesn't know which screen to show first.

3. Final Answer:

   You did not set a launcher activity in the manifest -> Option C

4. Quick Check:

   Missing launcher activity = crash [OK]

Hint: Always set launcher activity in manifest to avoid launch crashes [OK]

Common Mistakes:

• Assuming language choice causes this error
• Blaming Android Studio version without checking manifest
• Thinking device connection causes activity errors

5. You want to create a new Android project that uses Kotlin and includes a basic UI with a button and text. Which template should you select during project creation?

hard

A. Basic Activity

B. Empty Activity

C. No Activity

D. Fullscreen Activity

Solution

1. Step 1: Review available templates

   Empty Activity gives a 'Hello World!' screen; Basic Activity includes a button (FAB) and text by default.

2. Step 2: Choose Basic Activity for UI elements

   Basic Activity template sets up a screen with a button and text, ready for interaction.

3. Final Answer:

   Basic Activity -> Option A

4. Quick Check:

   UI with button = Basic Activity [OK]

Hint: Pick Basic Activity for ready-made button and text UI [OK]

Common Mistakes:

• Choosing Empty Activity expecting UI elements
• Selecting No Activity which has no UI
• Using Fullscreen Activity which is for immersive apps