Project structure and build basics in Kotlin

Introduction

Organizing your Kotlin project and building it correctly helps your code work well and be easy to manage.

When starting a new Kotlin app or library

When adding new files or features to your project

When you want to create a runnable program from your code

When sharing your code with others or publishing it

When fixing errors related to missing files or dependencies

Syntax

Kotlin

ProjectRoot/
 ├── build.gradle.kts
 ├── settings.gradle.kts
 ├── src/
 │    ├── main/
 │    │    ├── kotlin/
 │    │    │    └── YourCode.kt
 │    │    └── resources/
 │    └── test/
 │         ├── kotlin/
 │         └── resources/

build.gradle.kts is the Kotlin script file that tells how to build your project.

src/main/kotlin holds your main Kotlin code files.

Examples

This is a simple build script using Gradle Kotlin DSL to set up a Kotlin JVM project.

Kotlin

plugins {
    kotlin("jvm") version "1.8.0"
}

repositories {
    mavenCentral()
}

dependencies {
    implementation(kotlin("stdlib"))
}

This file names your project, which helps Gradle identify it.

Kotlin

settings.gradle.kts

rootProject.name = "MyKotlinApp"

Sample Program

This example shows a minimal Kotlin project setup with a build script and a main program that prints a message.

Kotlin

plugins {
    kotlin("jvm") version "1.8.0"
}

repositories {
    mavenCentral()
}

dependencies {
    implementation(kotlin("stdlib"))
}

// src/main/kotlin/Main.kt
fun main() {
    println("Hello, Kotlin project!")
}

Important Notes

Always keep your source code inside src/main/kotlin for main code and src/test/kotlin for tests.

Use Gradle commands like ./gradlew build to compile and build your project.

Keep your build scripts simple at first, then add dependencies as needed.

Summary

A clear project structure keeps your Kotlin code organized and easy to find.

Build scripts tell tools how to compile and package your code.

Using standard folders and Gradle helps your project work smoothly and be easy to share.