Gain insights into Kotlin’s basics, including variable declarations, data types, conditions, loops, and functions. Discover how to write simple Kotlin scripts and transition to advanced programming.

Kotlin is quickly joining the ranks of the most popular programming languages. Now that Google supports Kotlin for Android app development as the primary choice over Java, we’ll only see more developers making the switch. So if you’re looking to get started with Android app development, then you’ve come to the right place.

This course will be your guide on getting started with Kotlin. We’ll go over all the language basics including variable declarations, data types and the type system to conditions, loops, and functions.

After this course, you’ll be able to write simple Kotlin scripts and applications. With this solid understanding of the language basics, you’ll be able to more easily follow more advanced material covering functional and object-oriented programming.

Homam B.

What a brilliant course, its not too long so its fairly easy to get through in a weekend. Goes through the fundimentals of Kotlin in just the right amount of detail. I would recommend this as a first step into Kotlin language

"Brilliant course"

Patricio M.

I have completed the course and I have to say that it's extremely well done

The examples used are clear and easy to follow

The code is very clean and the instructor strives to write clear and concise code and he explains concepts very clearly

Kudos for a job well done!

"Extremely well done"

Alan J.

Clear explanations, and well organized. Highly recommended.

"Highly recommended"

Raphael A.

Excellent course. It's a beginner course in programming, but even as a Java programmer I've been able to remember a lot of things and get productive quickly in Kotlin. The course is well structured and the teacher knows the subject (I bought another course from the teacher).

"Excellent course"

Kotlin Crash Course for Programmers

Like lists and sets, arrays store multiple values in a linear data structure.

## What is an Array?

An array is a basic data structure in all programming languages. It stores multiple elements by placing them consecutively in memory. This structure is represented in the following illustration:

### What's the Difference Between Arrays, Lists, and Sets?

Sets are easy to distinguish from both lists and arrays based on their special properties: no ordering and no duplicates.

To understand the difference between lists and arrays, we'll have to look at the way their elements are stored and what implications this has for us as developers.

**While arrays store their values in one consecutive part of computer memory, list and set elements may be spread across memory.** This has several implications:
* **Arrays are a fixed-length data structure.** This is because, after the array is initially created, the next consecutive place in memory may be taken by another value. Thus, no more consecutive values can be added to the array. Not being able to add or remove elements distinguishes them from *mutable* lists.
* Differences between arrays and read-only lists exists only on a lower level, i.e., in the exact API they provide, the storage structure in memory, and their resulting runtime performance.

Finally, there's no differentiation between read-only and mutable arrays in Kotlin. Array elements can be overwritten but no elements can be added or removed, as they're fixed in length.

> **Note:** Recall that arrays are not part of Kotlin's Collections API. But they have a similar data structure, so they're mentioned here. All actual *collections* have read-only and mutable variants.

| **Data structure** | **Read-only available?** | **Ordered?** | **Duplicates allowed?** | **Memory storage** |
| ------------------ | ------------------------ | ------------ | ----------------------- | ------------------ |
| **List**           | Yes                      | Yes          | Yes                     | Non-sequential     |
| **Set**            | Yes                      | No           | No                      | Non-sequential     |
| **Array**          | No                       | Yes          | Yes                     | Sequential         |


## Creating an Array

Kotlin's API is very consistent when it comes to helper functions so the way to create an array should look familiar:

Like lists and sets, arrays store multiple values in a linear data structure.

# What is an Array?

An array is a basic data structure in all programming languages. It stores multiple elements by placing them consecutively in memory. This structure is represented in the following illustration:

## What's the Difference Between Arrays, Lists, and Sets?

Sets are easy to distinguish from both lists and arrays based on their special properties: no ordering and no duplicates.

To understand the difference between lists and arrays, we'll have to look at the way their elements are stored and what implications this has for us as developers.

**While arrays store their values in one consecutive part of computer memory, list and set elements may be spread across memory.** This has several implications:
* **Arrays are a fixed-length data structure.** This is because, after the array is initially created, the next consecutive place in memory may be taken by another value. Thus, no more consecutive values can be added to the array. Not being able to add or remove elements distinguishes them from *mutable* lists.
* Differences between arrays and read-only lists exists only on a lower level, i.e., in the exact API they provide, the storage structure in memory, and their resulting runtime performance.

Finally, there's no differentiation between read-only and mutable arrays in Kotlin. Array elements can be overwritten but no elements can be added or removed, as they're fixed in length.

> **Note:** Recall that arrays are not part of Kotlin's Collections API. But they have a similar data structure, so they're mentioned here. All actual *collections* have read-only and mutable variants.

| **Data structure** | **Read-only available?** | **Ordered?** | **Duplicates allowed?** | **Memory storage** |
| ------------------ | ------------------------ | ------------ | ----------------------- | ------------------ |
| **List**           | Yes                      | Yes          | Yes                     | Non-sequential     |
| **Set**            | Yes                      | No           | No                      | Non-sequential     |
| **Array**          | No                       | Yes          | Yes                     | Sequential         |


# Creating an Array

Kotlin's API is very consistent when it comes to helper functions so the way to create an array should look familiar:

Learn about the array data structure, how it differs from lists and sets, and how you can use them in Kotlin.

Hello Kotlin!

Variables and Data Types

Conditions

Collections

Loops

Functions

Equality Checks

Exception Handling

Summary

Arrays

What is an Array? #

What’s the Difference Between Arrays, Lists, and Sets? #