Environment Setup IDE

An Integrated Development Environment (IDE) provides code completion, debugging, and project management tools that make Kotlin development much easier. This guide covers setting up popular IDEs for Kotlin development.

Prerequisites

Install JDK (Java Development Kit)

Kotlin runs on the JVM, so JDK installation is required:

Step 1: Download JDK 8 or later from:

• ✅ Oracle JDK
• ✅ OpenJDK

Step 2: Install and verify:

java -version

Expected output:

java version "1.8.0_xxx" or higher

Recommended IDEs for Kotlin

1. IntelliJ IDEA (Recommended)

Best for: All Kotlin development (server-side, multiplatform, scripting)

Advantages:

• ✅ Created by JetBrains (Kotlin creators)
• ✅ Best Kotlin support and tooling
• ✅ Built-in Kotlin plugin
• ✅ Intelligent code completion
• ✅ Advanced refactoring tools

Download: IntelliJ IDEA

Editions:

• ✅ Community (Free): Perfect for learning Kotlin
• ✅ Ultimate (Paid): Additional features for web/enterprise development

2. Android Studio

Best for: Android app development

Advantages:

• ✅ Official Android IDE
• ✅ Based on IntelliJ IDEA
• ✅ Kotlin fully supported and recommended
• ✅ Android-specific tools and emulators

Download: Android Studio

3. Eclipse

Best for: Developers already familiar with Eclipse

Note: Requires Kotlin plugin installation

Download: Eclipse

4. Visual Studio Code

Best for: Lightweight development

Requirements: Install Kotlin extension from marketplace

Download: VS Code

Complete Setup: IntelliJ IDEA

Step 1: Download IntelliJ IDEA

1. Visit JetBrains IntelliJ IDEA
2. Choose your operating system
3. Download Community Edition (free) or Ultimate (trial/paid)

Step 2: Install IntelliJ IDEA

Windows:

1. Run the downloaded .exe file
2. Follow installation wizard
3. Choose installation directory (default is fine)
4. Select options:

• ✅ ✓ Create Desktop Shortcut
• ✅ ✓ Add "bin" folder to PATH
• ✅ ✓ Add "Open Folder as Project"

1. Click "Install"

macOS:

1. Open the downloaded .dmg file
2. Drag IntelliJ IDEA to Applications folder
3. Launch from Applications

Linux:

tar -xzf ideaIC-*.tar.gz
cd idea-IC-*/bin
./idea.sh

Step 3: First Launch Configuration

1. Accept License Agreement
2. Choose UI Theme: Light or Dark (Darcula)
3. Install Featured Plugins: Skip or select as needed
4. Kotlin plugin: Pre-installed (no action needed)

Step 4: Verify Kotlin Support

5. Open IntelliJ IDEA
6. Go to: File → Settings → Plugins (Windows/Linux)

• ✅ Or: IntelliJ IDEA → Preferences → Plugins (macOS)

1. Search for "Kotlin"
2. Verify Kotlin plugin is Enabled

Creating Your First Kotlin Project

Step 1: Create New Project

3. Click New Project on welcome screen
4. Select Kotlin from left sidebar
5. Choose Kotlin/JVM for general Kotlin projects
6. Click Next

Step 2: Configure Project

7. Project Name: Enter your project name (e.g., "HelloKotlin")
8. Location: Choose project directory
9. Build System: Select Gradle (recommended) or Maven
10. JDK: Select installed JDK (or download automatically)
11. Click Finish

Step 3: Project Structure

IntelliJ creates this structure:

HelloKotlin/
├── src/
│   └── main/
│       └── kotlin/
│           └── Main.kt
├── build.gradle.kts
└── settings.gradle.kts

Creating Your First Kotlin File

Step 1: Create Kotlin File

1. Right-click on src/main/kotlin/
2. Select New → Kotlin Class/File
3. Choose File
4. Name it: Main (extension .kt added automatically)
5. Click OK

Step 2: Write Code

In Main.kt, write:

fun main() {
    println("Hello from IntelliJ IDEA!")
}

Step 3: Run the Program

Method 1: Click the green play button (▶) next to main function

Method 2: Right-click in editor → Run 'MainKt'

Method 3: Keyboard shortcut:

• ✅ Windows/Linux: Ctrl + Shift + F10
• ✅ macOS: Ctrl + Shift + R

Step 4: View Output

The Run window appears at the bottom showing:

Hello from IntelliJ IDEA!

Process finished with exit code 0

IntelliJ IDEA Kotlin Features

1. Code Completion

As you type, IntelliJ suggests:

• ✅ Function names
• ✅ Variable names
• ✅ Keywords
• ✅ Import statements

Press Tab or Enter to accept suggestions.

2. Quick Fixes

Hover over red/yellow underlines for:

• ✅ Error explanations
• ✅ Quick fix suggestions
• ✅ Refactoring options

3. Code Formatting

Auto-format code:

• ✅ Windows/Linux: Ctrl + Alt + L
• ✅ macOS: Cmd + Option + L

4. Refactoring

Rename variables/functions safely:

• ✅ Right-click → Refactor → Rename
• ✅ Or: Shift + F6

5. Debugging

Set breakpoints and debug:

1. Click in left margin to add breakpoint (red dot)
2. Click debug icon (🐞) instead of run
3. Use debug controls to step through code

Android Studio Setup

For Android development:

1. Download Android Studio
2. Install with default settings
3. Launch Android Studio
4. Create New Project
5. Choose Empty Activity
6. Select Kotlin as language
7. Configure app details
8. Click Finish

Kotlin is pre-configured in Android Studio.

VS Code Setup

Step 1: Install Kotlin Extension

1. Open VS Code
2. Go to Extensions (Ctrl+Shift+X)
3. Search: "Kotlin"
4. Install "Kotlin Language" by mathiasfrohlich

Step 2: Install Code Runner (Optional)

5. Search: "Code Runner"
6. Install by Jun Han
7. Enables quick code execution

Step 3: Configure

Create settings.json:

{
    "code-runner.executorMap": {
        "kotlin": "kotlinc $fullFileName -include-runtime -d $fileNameWithoutExt.jar && java -jar $fileNameWithoutExt.jar"
    }
}

Comparison: Which IDE to Choose?

Tips for Beginners

1. Start with IntelliJ IDEA Community: Best learning experience
2. Use Code Completion: Type less, learn faster
3. Learn Shortcuts: Improves productivity significantly
4. Enable Auto-Import: Automatically imports needed classes
5. Use Built-in Terminal: No need to switch windows

Common Issues

Issue: "No JDK Configured"

Solution:

1. File → Project Structure → Project
2. Set Project SDK to your JDK
3. Apply changes

Issue: Kotlin Plugin Not Found

Solution:

1. File → Settings → Plugins
2. Search "Kotlin"
3. Install/Enable plugin
4. Restart IDE

Issue: Slow Performance

Solution:

1. Increase IDE memory: Help → Edit Custom VM Options
2. Add: -Xmx2048m (increase heap size)
3. Restart IDE

Next Steps

• ✅ Create your first Kotlin project
• ✅ Explore code completion features
• ✅ Learn essential keyboard shortcuts
• ✅ Try debugging with breakpoints
• ✅ Build a simple calculator app