Naming Packages in Kotlin

Introduction

Naming Packages is a fundamental concept every Kotlin developer should understand. Packages group related classes and functions into namespaces, keep large codebases organized, and control visibility with import statements.

Package names should be lowercase without underscores. In this tutorial you will learn the syntax, walk through a complete example program, study the sample output, and review best practices so you can apply the concept confidently in your own projects.

Definition

• Package names should be lowercase without underscores.
• Use meaningful hierarchical names such as com.company.module.
• Package structure should match folder structure in projects.

Syntax

package com.thiyagaraaj.kotlin.tutorial

Naming Packages in Kotlin Example Program in Kotlin

package com.thiyagaraaj.kotlin.tutorial

fun topic() = "Naming Packages"

fun main(args: Array<String>) {
    println(topic())
}

Sample Output

Naming Packages

When to use

Use packages to separate features (networking, UI, data) and avoid name clashes between similarly named classes.

How it works

1. The program starts with a main function — the entry point that runs when you execute the file.

2. The println(topic()) statement writes a line to the console — this produces part of the sample output below.

3. Package names should be lowercase without underscores.

4. Run the program in IntelliJ IDEA, Android Studio, or with the Kotlin command-line compiler (kotlinc / kotlin). Compare your console output with the sample output shown below.

Best Practices

• Understand the core idea: package names should be lowercase without underscores.
• Prefer readable names and small functions so examples map directly to real projects.
• Run and modify the example — change values and observe how the output changes.

Common Mistakes

• Skipping the example and only reading the definition — hands-on practice cements the concept.
• Copying syntax without understanding nullable vs non-nullable types or scope rules.
• Ignoring compiler warnings that often point to safer alternatives.

Key Points

• Package names should be lowercase without underscores.
• Use meaningful hierarchical names such as com.company.module.
• Package structure should match folder structure in projects.
• Test the example locally and verify the output matches the sample.
• Experiment by changing input values to see how behaviour changes.

Notes

• Semicolons at the end of statements are optional in Kotlin.