Kotlin for Beginners: Learn Programming With Kotlin
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Kotlin for Beginners: Learn Programming With Kotlin

Learn coding in Kotlin from scratch! Grasp object-oriented and functional programming and realize own coding projects!
4.7 (70 ratings)
Instead of using a simple lifetime average, Udemy calculates a course's star rating by considering a number of different factors such as the number of ratings, the age of ratings, and the likelihood of fraudulent ratings.
327 students enrolled
Created by Peter Sommerhoff
Last updated 4/2017
Current price: $25 Original price: $95 Discount: 74% off
30-Day Money-Back Guarantee
  • 5.5 hours on-demand video
  • 5 Supplemental Resources
  • Full lifetime access
  • Access on mobile and TV
  • Certificate of Completion
What Will I Learn?
  • Create professional applications using Kotlin, the new Java-based programming language developed by Jetbrains
  • Understand the concepts of the Kotlin language and how it integrates neatly with Java
  • Understand the basics of object-oriented software development, the most important development paradigm
  • Understand the principles behind other object-oriented languages like Java, C++, PHP, C#, Scala, or Swift
  • Use Intellij, the popular Java (and Kotlin) IDE, to write code effectively and professionally
  • Read code and write your Kotlin code as well
View Curriculum
  • We will go through all setup you need in order to use Kotlin
  • You must be able to install new software on your computer (JDK + IntelliJ), we will go through the actual process inside the course.

>> Learn programming in Kotlin, the most beautiful modern programming language based on Java!

>> Join this beginner-friendly course to learn to write code with an awesome and easy-to-learn language!

>> Expand your expertise as a Java or Android Developer and improve the quality of your code!

>> I'll answer every question you have, help you personally if you get stuck and listen to your feedback! Join 15,000+ happy students of mine on Udemy!

This course will teach you programming in Kotlin! We begin with the basics so this course is completely suitable for beginners. You will put what you learn into practice in several coding challenges. So at the end, you'll be able to create your own applications in Kotlin.

Topics covered include:

  • Variables & nullable types (null safety)
  • Conditionals: if and when
  • Loops: for and while
  • Functions
  • Object orientation: classes, objects, interfaces, inheritance etc.
  • Data classes (a handy feature in Kotlin)
  • UPDATE 03/2017: more object-orientation + binary and hexadecimal numbers
  • UPDATE 04/2017: the information hiding principle + generics
  • ...this course keeps growing based on your feedback!

This course also covers object-orientation, the major development paradigm you need to grasp in today's world. But we will also look at functional programming concepts that will make your life much easier.

Once you understand these, you will also be able to understand other object-oriented languages, including Java, PHP, C++, C#, Scala, or Swift. They all use this same basic paradigms.

Throughout the course, you can always contact me personally to get help when you're stuck. I check the discussions regularly to help you at every step along the way.

Also, this course will be extended and refined in the future based on student feedback. I really appreciate each and every of my students so I listen to your feedback and act on it.

So get in now to help shape this course and become part of the community inside!

Who is the target audience?
  • You do not need programming skills, we will start from scratch and slowly make our way to intermediate and more advanced topics
  • You should be excited to learn an awesome new programming language!
  • You will need basic skills in handling a PC, so you should know how to install and run applications on your computer.
Curriculum For This Course
Expand All 58 Lectures Collapse All 58 Lectures 05:36:42
3 Lectures 07:14

What YOU will create while following along this course, starting out with a simple "Hello World" program and creating more sophisticated programs over time.

After the course, you'll have all the fundamentals you need to start diving into other programming languages and learn more advanced concepts. The course will also be extended over time to cover more such advanced topics.

This course will start with the basics and cover conditional statements, functions, lists and arrays, classes and objects, inheritance and more about object-orientation. We will also learn some functional programming examples.

Preview 01:57

Udemy interface: Please make sure you are watching in HD! Also set your playback speed according to your preferences, that's a really useful feature. For questions, check out the discussions.

Following along: Take all the quizzes! They only take a few minutes and recap the most important points. Rock it in the discussions(!) so that I can help you when you get stuck and improve this course. Code along in every lesson, bring your own projects to life, and make it to the end!

Preview 04:26

New lectures will be added to this course. If you have any suggestions for new topics or find any problems in a lecture, please let me know and I will then update that lecture!

Preview 00:51
What is Kotlin?
2 Lectures 06:16

Kotlin is an object-oriented languages with functional features as well. It facilitates many things, provides null safety and offers a concise and readable syntax.

Preview 05:12

On try.kotlinlang.org (check link in the resources), you can try out some sample applications and get to know the basics of Kotlin. It is a great playground for simple code snippets.

Preview 01:04
Getting the Tools
3 Lectures 09:39

This lectures guides you through the process of downloading the latest Java Development Kit (JDK) we need to use Kotlin.

Preview 02:46

In this step, we download the free and powerful IntelliJ Community Edition from the Jetbrains website. This is an Integrated Development Environment (IDE) that provides awesome support for Kotlin, Java, and many other languages. It is also the IDE used by Google for Android App Development.

Preview 01:54

Learn how to adjust the editor theme and font size in IntelliJ to your personal preferences and how to create the first project.

Preview 04:59
Getting Started With Kotlin!
6 Lectures 36:57

In this lecture, we use Kotlin interactively in the REPL (read-eval-print-loop) as a calculator, learn how to assign values and run some simple commands.

Preview 05:31

This lecture covers how to create variables in Kotlin, when to use val vs. var and why you prefer val over var when creating variables to enforce immutability.

Preview 04:01

3 questions

This lecture covers all basic types available in Kotlin plus strings to store text.

Basic types in Kotlin include Byte, Short, Int, Long, Float, Double, Boolean, and Char. This lecture guides you through each of them and their differences.

Preview 09:51

Variables and Data Types
4 questions

Expressions are pieces of code that have a value, such as 4*(3+5) or listOf(1,2,3,4,5). We can assign the values of expressions to variables and the Kotlin REPL will print an expression's value right below it whenever we type in an expression.

Statements on the other hand don't carry a value, such as print("Hello there") or val a = 4. Assignments are a special type of statements because they also don't have a value.

Expressions vs. Statements

Check your understanding of the differences between expressions and statements.

Expressions vs. Statements
3 questions

In contrast to languages like Java, Kotlin offers null safety through explicit nullable types!

Learn how to create nullable variables and why you should avoid this. You will also understand the advantages of having to make variables explicitly nullable to avoid NullPointerExceptions.

Preview 07:22

4 questions

Now it's time to create our very first stand-alone Kotlin application!

You will create a simple "Hello World" app and be guided through the process of creating a main() function as the entry point to your application.

Preview 04:31
Conditional Statements
6 Lectures 22:47

Learn how to use if statements for handling conditional program flow. So this concept lets you define different program behavior based on conditions you can define.

Conditional Statements Using "if"

if Statements
2 questions

This lecture covers the use of when statements to handle a fixed set of possible options.

In contrast to if statements, these do not allow arbitrary conditions and are commonly used to switch between a number of distinct cases based on the value of a variable.

Conditional Statements Using "when"

when Statements
1 question

Learn when to use if statements vs. when statements.

If statements allow defining arbitrary conditions and are the most common choice to handle control flow. In some cases however, when statements express your intentions better. That is, when you want to switch application behavior based on some distinct values of a variable.

When statements can always be simulated by if statements.

When to Use "if" vs "when"

Conditional Statements Using "if" and "when"
2 questions

In Kotlin, we can use conditional statements as expressions with a value. In fact, every if or when statement is an expression in Kotlin and we can, for example, save its value into a variable.

The last expression in each block of an if or when expression defines the value of the whole if or when expression if that block is executed.

Conditional Expressions

Inside when blocks, we can actually use more sophisticated expressions on the left side than just plain values. More specifically, Kotlin allows us to check for ranges, types, values of function calls and more on the left side of each condition in when constructs.

More Advanced "when" Constructs

Advanced Conditionals
4 questions

Coding Challenge: Put your knowledge of conditionals into practice by generating random numbers and checking which range they fall into.

Coding Challenge: Conditionals
1 page
Arrays and Lists
3 Lectures 17:44

Learn about two super important data types of every programming languages: Arrays & Lists!

What are arrays? What are lists? This lecture goes through each of them and explains their differences and similarities. You will also learn when to use arrays vs. lists which is a question you find many people asking online.

Arrays vs. Lists

Learn how to create, modify, and access arrays in Kotlin using the square bracket notation. This allows you to store multiple elements inside a single variable.

Later, we will also see how to loop over arrays to perform some tasks on each of its elements.

Arrays in Kotlin

This lecture guides you through the process of creating, modifying, and accessing lists in Kotlin. We will see that we can work with lists in a similar way as we do with arrays, but that there are also some differences to keep in mind.

Lists in Kotlin

Arrays and Lists in Kotlin
5 questions
Lucky Loop
5 Lectures 18:42

Learn how to use for loops in Kotlin to loop over an array/list or to repeat a certain block of code a certain number of time (when you know in advance how many iterations you will need).

"for" Loops

Learn how to use while loops in Kotlin to repeat blocks of code, similar to for loops. But when using while loops, you don't need to know the number of iterations in advance. The while loop allows you to define arbitrary conditions which must be true for the loop to continue.

"while" Loops

Loops Using "for" and "while"
4 questions

The break and continue statements allow you to completely skip over a loop or to skip to the next iteration, respectively. So with break, you can stop a loop and go on with execution right after it. Whereas with continue, you can skip to the next iteration of a loop to avoid unnecessary computation.

The break statement is useful, for example, when you are only interested in the first occurance of something. For instance, to check if an array contains a certain value, you just need to check until you find it. After finding that first occurance, you can skip the rest of the loop.

The continue statement is useful to skip computations in unnecessary iterations. For example, if you only want to do something with String of length > 2, you can skip iterations with a shorter string when you iterate over a list of strings.

Using "break" and "continue" Statements

Learn how to use loop labels and then address them in break and continue statements. This allows you to break or continue an outer loop when inside a nested loop.

Naming loops

Using break, continue and return
3 questions

What's the sum of all numbers from 100 to 100,000?

Coding Challenge: Using Loops
1 page
Congrats Novice!
2 Lectures 04:03

Congratulations! By making it this far, you are already ahead of 90% of the other students. Keep going!


Recap of all topics covered so far, including variables, data types, nullable types, conditionals, arrays, lists, and loops.

All The Basics (Recap What You've Learned!)
7 questions

Another programming task for you to practice what you learned.

Keep going! The best topics are still to come!

Coding Challenge: Loops, Lists and Conditionals
1 page
2 Lectures 18:24

This lecture teaches you one of the most important concepts that applies not only to Kotlin but all other programming languages as well: creating and using functions!

Functions are self-contained pieces of code that can take in parameters and may return a value. Parameters allow passing in information into the function when calling it, so that the function can then work with that data and perform computations on it.


3 questions

Let's see how to reverse a list using a loop. This is a functionality that often comes in handy when working with ordered collections like lists and arrays.

This code along gives you some more intuition on how to work with loops if you've never worked with them before. It also helps you internalize how to write loops in Kotlin. And of course, it's guides you into what a programmer does all day: implementing algorithms. Reversing an ordered collection is great little algorithm to start with.

Code Along: Reversing A List
Object-Oriented Programming -- Part I
10 Lectures 01:00:12

Object-orientation is the most widely used software development paradigm. Popular programming languages are mostly focused on object-oriented development, including Java, Python, C++, C#, PHP, and Swift.

This lecture explains all the major elements of object-orientation: classes, objects, interfaces, data, and methods. It also goes through the concept of creating an abstraction of the real world by modeling objects.

Starting with Object-Orientation

The Basics of Object-Orientation
3 questions

Let's create our first class in Kotlin!

This lectures guides you through creating basic classes, adding properties to classes, creating objects from it and accessing its properties. Classes are like blueprints from which we can create objects and they contain properties and methods. The next lecture will cover methods.

Our First Class

While properties define what data a class holds, methods define functionality and can execute.

This lecture teaches you how to add methods to classes, which are essentially just functions inside a class. We can then call those methods on our class.


Properties and Methods
4 questions

Coding Challenge: Classes
1 page

Learn how to define basic constructors in Kotlin to define how exactly objects are supposed to be created from a class. Parameters can be added to the constructor to add properties to the class and define what information/data an object needs to be instantiated.


Object Creation
2 questions

This lecture covers how to use named parameters and default values for function and constructor calls. This is super handy to make the code more readable and also allows you to change to order of the parameters when calling the constructor or function.

Named Parameters & Default Values

Named Parameters & Default Values
4 questions

Learn how and when to use open classes in Kotlin to allow inheritance. This also includes how to extend classes, implement interfaces, and how to override methods and properties

Open Classes and Inheritance

Open Classes and Inheritance
2 questions

Learn how and when to use the "abstract" keyword in Kotlin, what exactly abstract classes are and when you should use them.

Abstract Classes

Abstract Classes
3 questions

You can use the open keyword to allow inheriting from a class or overriding a property/method vs. the abstract keyword to require inheriting and overriding.

Open vs. Abstract

Open vs. Abstract
3 questions

Interfaces are like contracts that classes may adhere to (meaning they implement that interface). This lecture explains...

  • how you can create interfaces,
  • what constraints there are in interfaces,
  • the importance of interfaces in object-oriented programming,
  • and the differences compared to classes.

4 questions

Object-Orientation - Part I
3 questions
3 More Sections
About the Instructor
Peter Sommerhoff
4.6 Average rating
824 Reviews
17,481 Students
4 Courses
Developer & Software Engineer - With 15,000+ Happy Students

Hi, it's Peter, glad you made it here! If you're anything like me, you want to always keep learning, master new skills, and ultimately achieve your life goals -- whether that's a well-paying career, traveling the world, working from the comfort of your home, or sharing your expertise with and helping other people.

Does that sound like you? Then make sure to enroll in one my courses and learn about awesome programming languages, software design, productivity, or anything else you're interested in!

I feel honored for every student I have and will make sure you have a great learning experience. You can always ask me personally if you get stuck or have anything at all I can help you with.

So please check out my courses below and I'll see you there!