Kotlin to Ruby

Free Kotlin to Ruby Code Converter

No email required. 100% free. Done in 30 seconds.

Transform your code from Kotlin to Ruby with our free AI-based code convertion tool. If you like what you see, we also create documentation for your code! We don't ever store your code or any representation of it in our databases, but it will be shared with the LLM of our choice for processing.

Other tools






Ionic + Angular










React Native


Ruby on Rails






How to convert from Kotlin to Ruby

If you are proficient in Kotlin and looking to transition your code to Ruby, understanding the intricacies of both languages is crucial. This guide serves as a Free Kotlin to Ruby Code Converter to help you manually convert your Kotlin code into Ruby.

Understanding the Basics

Syntax Differences

Kotlin and Ruby have different syntaxes, and understanding these differences is the first step in converting code.

  • Kotlin: Statically typed language.
  • Ruby: Dynamically typed language.

In Kotlin, you might see:

val message: String = "Hello, World!"

In Ruby, it would be:

message = "Hello, World!"

Variable Declaration and Types

In Kotlin, you declare variables using val for immutable variables and var for mutable variables. Ruby, being dynamically typed, doesn't require explicit declaration types.

  • Kotlin:

    val x: Int = 5
    var y: String = "Kotlin to Ruby"
  • Ruby:

    x = 5
    y = "Kotlin to Ruby"

Converting Functions and Methods

Function Declaration

Kotlin uses the fun keyword to declare functions, while Ruby uses the def keyword.

  • Kotlin:

    fun greet(name: String): String {
        return "Hello, $name"
  • Ruby:

    def greet(name)
      "Hello, #{name}"

Default Parameters

Kotlin allows for setting default parameters in functions; Ruby handles default parameters similarly, but the syntax is different.

  • Kotlin:

    fun greet(name: String = "World"): String {
        return "Hello, $name"
  • Ruby:

    def greet(name = "World")
      "Hello, #{name}"

Handling Conditionals

If-Else Statements

The structure of if-else statements in Kotlin and Ruby is another area of difference.

  • Kotlin:

    if (x > 10) {
        println("Greater than 10")
    } else {
        println("10 or less")
  • Ruby:

    if x > 10
      puts "Greater than 10"
      puts "10 or less"

When vs Case Statements

Kotlin's when statement is akin to Ruby's case statement.

  • Kotlin:

    when (x) {
        1 -> println("One")
        2 -> println("Two")
        else -> println("Other")
  • Ruby:

    case x
    when 1
      puts "One"
    when 2
      puts "Two"
      puts "Other"

Collections and Loops

Lists and Arrays

Kotlin has explicit support for different types of collections like Lists and Arrays, while Ruby primarily uses Arrays.

  • Kotlin:

    val list: List<Int> = listOf(1, 2, 3)
    val array: Array<Int> = arrayOf(1, 2, 3)
  • Ruby:

    list = [1, 2, 3]
    array = [1, 2, 3]

For Loops

The way you implement loops will also change.

  • Kotlin:

    for (i in 1..3) {
  • Ruby:

    (1..3).each do |i|
      puts i

Error Handling

Try-Catch and Rescue

Kotlin uses try-catch for error handling, while Ruby uses begin-rescue blocks.

  • Kotlin:

    try {
        val result = riskyOperation()
    } catch (e: Exception) {
        println("Caught an exception: ${e.message}")
  • Ruby:

      result = risky_operation
    rescue Exception => e
      puts "Caught an exception: #{e.message}"

Converting Classes and Objects

Class Declarations

Kotlin's class declarations are more verbose compared to Ruby.

  • Kotlin:

    class Person(val name: String, val age: Int)
  • Ruby:

    class Person
      attr_accessor :name, :age
      def initialize(name, age)
        @name = name
        @age = age

Practical Example

Let’s take a Kotlin program that prints a greeting and convert it to Ruby.

Kotlin Version:

fun main() {
    val name = "Kotlin"

fun greet(name: String): String {
    return "Hello, $name"

Ruby Version:

def greet(name)
  "Hello, #{name}"

name = "Kotlin"
puts greet(name)


Transitioning your code from Kotlin to Ruby necessitates a keen understanding of both languages' paradigms. This Free Kotlin to Ruby Code Converter guide has walked you through essential concepts such as variable declaration, function conversion, conditionals, loops, error handling, and class declarations.

By mastering these fundamental differences, you'll be able to migrate your codebase efficiently and take advantage of Ruby's unique features.

Document your code using AI

Sign up now
& free your developers' time

Start for free

Join thousands of companies documenting their code using AI.

Frequently Asked Questions

This free AI tool does its best to generate professional documentation. However, it's missing some context from other related files. The paid version takes into account different files to generate documentation for each use case, apart from the documentation of every file. You have also the possibility of add custom concepts to improve the knowledge of your codebase.

No. You don't have to enter any personal information to use Codex's free code documentation tool — it's 100% free.

No. An encrypted version of your code is stored only while its being processed and it's deleted immediately.

If you can work with a custom Azure model in your own account, let us know. If not, Codex also works with open source models that can run on-premises, on your own servers, so your data is always yours. Feel free to get in touch with us!