Creating a new Android project in Android Kotlin

Introduction

Creating a new Android project is the first step to build your own mobile app. It sets up all the files and tools you need to start coding.

When you want to start building a new Android app from scratch.

When you want to practice Android development with a fresh setup.

When you need to create a sample app to test ideas or learn new features.

When you want to organize your app code and resources in one place.

Syntax

Android Kotlin

1. Open Android Studio.
2. Click on 'New Project'.
3. Choose a project template (e.g., Empty Activity).
4. Enter your app name, package name, and save location.
5. Select language as Kotlin.
6. Choose minimum SDK version.
7. Click 'Finish' to create the project.

The project template helps you start with some basic code and layout.

The minimum SDK version decides which Android devices your app can run on.

Examples

This creates a simple app with one screen using Kotlin.

Android Kotlin

Open Android Studio > New Project > Empty Activity > Name: MyFirstApp > Language: Kotlin > Minimum SDK: API 21 > Finish

This creates an app with a toolbar and floating button ready to customize.

Android Kotlin

Open Android Studio > New Project > Basic Activity > Name: WeatherApp > Language: Kotlin > Minimum SDK: API 23 > Finish

Sample App

This is the main activity Kotlin file created by default. It loads the layout file activity_main.xml which shows a "Hello World!" message.

Android Kotlin

package com.example.myfirstapp

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

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

Important Notes

Android Studio automates many setup steps so you can focus on coding.

Always choose Kotlin for new Android projects as it is the recommended language.

You can change the app name and package later but it is easier to set them correctly at the start.

Summary

Creating a new Android project sets up your app's structure and files.

Use Android Studio's wizard to pick templates, name your app, and select Kotlin.

The default code shows a "Hello World!" screen ready for you to add your app features.

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