[Setup] Kotlin Development Environment

A JDK (Java Development Kit) is required to compile and run Kotlin programs.

1. Download the JDK from Adoptium or Oracle.
2. After installation, verify with the following command.

java -version

If version information is displayed, the JDK installation is complete.

There are several ways to install the Kotlin compiler.

Method	Description
SDKMAN	A version management tool for macOS / Linux. This is the recommended method.
Homebrew	On macOS, you can install via Homebrew.
Manual install	Download directly from kotlinlang.org.

To install with SDKMAN:

sdk install kotlin

To install with Homebrew:

brew install kotlin

After installation, verify with the following command.

kotlinc -version

1. Create the source file

Use a text editor to create a file named hello.kt with the following content.

fun main() {
    println("Hello, World!")
    println("The Kotlin environment is set up successfully.")
}

2. Compile

kotlinc hello.kt -include-runtime -d hello.jar

-include-runtime bundles the Kotlin runtime into the JAR, producing a self-contained file that can be run with just Java.

3. Run

java -jar hello.jar

If Hello, World! and The Kotlin environment is set up successfully. are displayed, you're all set.

If you want to try Kotlin without setting up a local environment, Kotlin Playground is a great option. You can type code in your browser and see the results immediately.

A good approach is to experiment with the syntax in Playground during the early stages of learning, then set up a local environment when you are ready for more serious development.

Tool	Description
IntelliJ IDEA	The IDE from JetBrains, the creators of Kotlin. Offers the best Kotlin development experience. The Community edition is free.
Android Studio	An IDE for Android app development. Based on IntelliJ IDEA with native Kotlin support.
Visual Studio Code	Installing the Kotlin extension adds syntax highlighting and code completion.

If your terminal displays kotlinc: command not found, the PATH may not be configured correctly. Follow the steps below to check and fix the issue.

1. Find the command location

Check where the command is located.

which kotlinc
which kotlin

If not found, check common installation locations.

ls /opt/homebrew/bin/kotlinc
ls ~/.sdkman/candidates/kotlin/current/bin/kotlinc

2. Check which shell you are using

echo $SHELL

If /bin/zsh is shown, edit ~/.zshrc; if /bin/bash is shown, edit ~/.bashrc.

3. Add to PATH

Once you know the command location, add the PATH to your shell configuration file.

If installed with Homebrew (macOS zsh):

echo 'export PATH="/opt/homebrew/bin:$PATH"' >> ~/.zshrc
source ~/.zshrc

If installed with SDKMAN (macOS zsh):

echo 'export PATH="$HOME/.sdkman/candidates/kotlin/current/bin:$PATH"' >> ~/.zshrc
source ~/.zshrc

For Linux (bash):

echo 'export PATH="$HOME/.sdkman/candidates/kotlin/current/bin:$PATH"' >> ~/.bashrc
source ~/.bashrc

If you are using SDKMAN

If Kotlin installed via SDKMAN is not found, the shell initialization may be missing. Make sure the following is present in your shell configuration file.

SDKMAN initialization script:

export SDKMAN_DIR="$HOME/.sdkman"
[[ -s "$HOME/.sdkman/bin/sdkman-init.sh" ]] && source "$HOME/.sdkman/bin/sdkman-init.sh"

Also check the JDK PATH

Since Kotlin runs on the JVM, the java command must also be available. If java -version returns an error, configure the JDK PATH as well.

For Windows, go to "Advanced System Settings" → "Environment Variables" → "Path" and add paths for both Kotlin and the JDK.