Teach on Udemy

Turn what you know into an opportunity and reach millions around the world.

Learn More

Your cart is empty.

Keep shopping

Kotlin for Java Developers

Name: Kotlin for Java Developers
Rating: 4.5 (5526 reviews)

Use your Java skills to learn Kotlin fast. Enhance career prospects and master Kotlin, including Java interoperability

Bestseller

Created byTim Buchalka, Goran Lochert, Tim Buchalka's Learn Programming Academy

Last updated 4/2025

English

What you'll learn

Create Kotlin programs
Understand the differences between Java and Kotlin
Understand how Java and Kotlin programs interoperate

Course content

11 sections • 92 lectures • 16h 46m total length

Instructor Introduction and Course Transition Overview with Tim Buchalka3:05
Kotlin for Java Developers: Prerequisites, Course Outline, and Objectives6:01
Activating Your Six-Month Free IntelliJ IDEA Ultimate Edition Trial1:29
Step-by-Step Guide to Downloading and Installing JDK 8 on Windows5:15
Comprehensive Guide: Downloading and Installing JDK 8 on Mac Systems2:44
Downloading and Installing the Java Development Kit (JDK) 8 on Ubuntu Linux4:20
Setting Up IntelliJ IDEA on Windows: Download, Installation, and Configuration9:35
Comprehensive Guide to Installing and Configuring IntelliJ IDEA on macOS9:28
Learn how to download, install, and configure IntelliJ IDEA on macOS, including choosing editions, launching the app, and setting up the JDK, SDK, and editor preferences.
Installing and Configuring IntelliJ IDEA on Linux: A Step-by-Step Guide10:03
Download and install IntelliJ IDEA on Linux 16.04, choosing the community edition, compare with ultimate edition, and configure a desktop entry plus the Java JDK as the project SDK.
Configuring IntelliJ IDEA for Optimal Kotlin Development and Coding Practices9:59
Enable and verify the Kotlin plugin in IntelliJ, adjust Kotlin settings such as parameter name hints and code style, and learn about labeling parameters and the Java to Kotlin converter.

Section Overview: Exploring Kotlin's Purpose and Practical Application0:29
What is Kotlin? Exploring Origins, Principles, and Java Interoperability6:04
Analyzing the Java Text Adventure Game: Code Structure and Functionality13:21
Analyze the Java text adventure game and its code structure as we prepare a Kotlin conversion, including console gameplay and locations and exits data.
Hands-on Conversion: Transforming the Java Text Adventure Game to Kotlin21:42
Leveraging IntelliJ IDEA's Automatic Java-to-Kotlin Code Converter4:31
IntelliJ converts Java to Kotlin when you paste Java into a Kotlin file, illustrating Java–Kotlin interoperability, with the converter offering a starting point that may be verbose or require refinement.

Kotlin Section 3 Kickoff: Diving into Syntax Differences and Key Concepts0:37
Crafting Your First Kotlin Program: "Hello World" Example and JVM Execution9:15
Exploring the Kotlin Standard Library: Packages, Default Imports, and API4:25
Explore the Kotlin standard library and its default imports, including kotlin and kotlin.io, and learn how they enable array and print line usage without explicit imports.
Kotlin Variable Declarations: Understanding 'val', 'var', and Type Inference12:07
Creating Type Aliases in Kotlin: Simplifying Complex Types for Readability3:14
Create type aliases in Kotlin to alias existing types and reduce typing, improving readability; alias strings like string builder to java.lang.stringbuilder, and use top-level declarations with imports for reuse.
Kotlin vs. Java: Concise Syntax, Null Safety, and Standard Library Usage10:01
Explore Kotlin vs. Java differences, including concise syntax with no semicolons and bracket access for collections. Learn about wrappers, soft keywords, the Kotlin string class, unchecked exceptions, and top-level functions.
Understanding Equality in Kotlin: Referential (===) vs. Structural (==)13:20
Kotlin Bitwise Operators and Smart Casting: Streamlined Type Handling6:08
Discover how Kotlin handles bitwise operators by spelling them out, and use the is operator for type checks with smart casting that eliminates explicit casts for verified types.
Enhancing String Manipulation with Kotlin's Powerful String Templates7:49
Mastering Raw Strings in Kotlin: Multi-line and Unescaped Text Handling8:08
Interactive Kotlin Development: Utilizing the Read-Eval-Print Loop (REPL)4:00
Foundational Kotlin Syntax and Project Setup: A Practical Exercise Series14:42

Kotlin Data Types and Nullability: An Introduction to Section 4 Concepts0:46
Kotlin's Primitive Types: Int, Byte, Short, Long, Float, Double, Char, Boolean20:08
Explore Kotlin's primitive types and how everything is a class. Learn that Kotlin does not auto widen numbers and how to convert to data types with conversion functions.
Working with Arrays in Kotlin: Creation, Initialization, and Primitive Types23:08
Preventing NullPointerExceptions: Kotlin's Nullable Types and Safe Calls -Part 121:04
Explore how Kotlin uses nullable types and the safe call operator to prevent null pointer exceptions, and learn to use the Elvis operator and safe casts for concise null handling.
Advanced Null Safety: The Elvis Operator and Not-Null Assertions in Kotlin-Part14:47
Explore how to safely handle nullable values in Kotlin by using the safe-call operator, the not-null assertion, and the let function to conditionally invoke code.
Creating Arrays of Nullable Types6:19
Data Types, Nullability, and Arrays: Kotlin Practice Exercises15:58

Object-Oriented Fundamentals: Introduction to Kotlin Classes and Functions0:45
Kotlin Visibility Modifiers: Public, Private, Protected, and Internal9:17
Mastering Kotlin Class Declarations and Constructor Usage: A Deep Dive22:23
Explore Kotlin class declarations, primary constructors, and property initialization with val or var, including initializer blocks, secondary constructors, and default parameter values to reduce boilerplate.
Understanding Kotlin Properties, Backing Fields, Getters and Setters12:28
Using Top-Level and Constant Values and Data Classes in Kotlin Projects12:10
Introduce top-level constants to Kotlin and use data classes for state storage. Explore automatic toString, equals, hashCode, and copy in a car example, with primary constructor properties and immutable vals.
Comprehensive Guide to Function Declaration and Usage in Kotlin21:53
Enhancing Code Reusability with Kotlin Extension Functions11:44
Streamlining Code with Inline Functions in Kotlin: Optimisation Guide2:42
Implementing Inheritance, Part One: Base Classes and Subclasses in Kotlin11:24
Advanced Inheritance in Kotlin: Overriding, and Secondary Constructors14:09
Mastering Interfaces in Kotlin: A Comprehensive Guide for Developers8:00
Learn how Kotlin interfaces compare to Java: declare interfaces, extend them, and implement across classes. Explore properties in interfaces, abstract vs concrete, and absence of backing fields or constructors.
Simplifying Kotlin Development Using Singletons with the Object Keyword6:05
Mastering Companion Objects: Alternatives for Static Members in Kotlin13:40
Creating Anonymous Objects: Implementing Interfaces in Kotlin with Object6:35
Creating and Configuring Enums in Kotlin: A Step-by-Step Tutorial4:10
Mastering Kotlin Imports: Packages, Top-Level Functions, and Modules16:45
Kotlin's Internal Access Modifier: Visibility within Modules Explained5:23
Learn how Kotlin's internal modifier restricts visibility to the same module, compare it with private at the file level, and use IntelliJ's optimize imports to clean up unused imports.
Hands-On Kotlin: Object-Oriented Programming Challenges - Part 120:12
Putting It All Together: More Kotlin OOP Challenges - Part 219:19

Kotlin Control Flow: Loops, 'if', 'when', 'try/catch' Expressions Unveiled0:36
Kotlin For Loops: Mastering Ranges, Iteration, and Advanced Control Flow27:57
Kotlin's 'if' as an Expression: Replacing the Ternary Operator with Clarity9:52
Explore how Kotlin's if acts as an expression that returns a value, replacing the ternary operator, with examples of using else branches and results in strings.
Kotlin's 'when' Expression: Supercharged Switch Statements for Every Scenario22:15
Kotlin Error Handling: Using 'try/catch' as an Expression for Concise Code11:58
Putting it all together, range, for, if, when, and try/catch expression23:26

Introduction to Kotlin Generics, Collections, and Lambda Expressions0:57
Kotlin Lambda Expression Fundamentals: Syntax, Usage, and 'run' Function12:55
Kotlin Lambdas with Receivers: 'with' and 'apply' for Concise Code19:15
Explore Kotlin lambdas with receivers using with and apply to write concise code, learn receiver objects, and master local and non-local returns with labels and nested apply patterns.
Kotlin Lists: Immutable and Mutable, Basic Operations, and Java Interop16:25
Advanced Kotlin List Functions: 'filter', 'map', 'zip', 'union', 'distinct'9:56
Kotlin Maps and Destructuring Declarations: Efficient Data Handling15:37
Exploring Sets Data Structures: Unique Element Groupings within Kotlin6:28
More Kotlin Collection Functions: Exploring Additional Tools Beyond Basics16:13
Explore Kotlin's collection functions beyond basics, including filter, map, all, any, count, find, group by, sorting, and sequences, applied to car data and maps with mutable and immutable examples.
Kotlin Sequences: Optimising and Efficiently working with large collections15:54
Deep Dive on Generics with Kotlin: Understanding type parameters and Erasure10:50
Delve into Kotlin generics by exploring type parameters, compile-time type safety, and extension functions on lists, showing how generic usage reduces casting and clarifies code.
Understanding and working with Generics: Limiting Types with Constraints22:27
Unlocking the power of Reified parameters: Accessing Type Information Runtime8:38
Understand how reified type parameters overcome runtime type erasure in Kotlin by inline functions, enabling type checks and filtering elements by type.
Deep Dive into Generics: Understanding Covariance for Enhanced Flexibility27:35
Mastering Contravariance, and understanding superclasses, and subclasses.20:56
Understanding use-site variance, and type projection in Kotlin Generics10:46
Explore use-site variance and type projection in Kotlin generics by covarying the copy cars function source, enabling copying Ford or car lists into a car list, contrasted with Java wildcards.
Title: Hands-On Kotlin: Data Classes, Collections, Lambdas, and Variance27:01

Introduction to Kotlin File I/O: Leveraging Java I/O Classes0:40
Reading Text Files in Kotlin: Readers, readText, and use16:24
Kotlin Binary File Reading, Java I/O, and use for Resource Management7:34
This lecture shows reading binary files in Kotlin with Java I/O, using DataInputStream and FileInputStream, and explains read bytes for managing resources with use.
Kotlin File Tree Traversal: walk, walkTopDown, and Sequences6:16

Calling, Converting, and Influencing: Mastering Kotlin and Java Interop1:31
Handling Nullability: Using Java Code Safely from Kotlin14:50
Accessing Java from Kotlin: Properties, Exceptions, Varargs, and More17:17
Learn how Kotlin accesses Java via properties getters and setters, handles exceptions, uses varargs with spread, works with primitive arrays, and leverages static members, Object, and SAM interfaces with lambdas.
Calling Kotlin Functions and Accessing Top-Level Items from Java Code16:21
Using Annotations for Seamless Kotlin to Java Interoperability17:32
Solving Java to Kotlin Interoperability Issues with Annotations25:07

Kotlin Course Section 10: Introduction - Reviewing What You've Learned1:06
Deep Dive into Kotlin: Revisiting the Converted Text Adventure Application10:01
Kotlin for Java Developers: Full Course Recap and Further Learning Paths2:25
Recap the key differences between Kotlin and Java data types and outline core Kotlin concepts: classes, interfaces, inheritance, generics, collections, lambda expressions, and file IO, plus Java interoperability.
Your Feedback Matters: Help us Improve the Course with Your Suggestions!0:13

Requirements

Ideally, have at least a basic knowledge of Java (not essential)
A computer running Windows, Mac OS X or Linux

Description

Are you a Java developer wondering if you need to learn Kotlin?

Maybe you are an experienced Java developer who wants to learn Kotlin quickly, to be prepared for future project work.

Perhaps instead, you're an Android app developer who knows Java well, but you want to be able to move forward with Kotlin for new Android development work.

Well, with Google's recent focus on Kotlin for Android app development, this language has been launched into the mainstream, and you can be sure you will be seeing a lot more about it. It's also highly likely that you will be working with Kotlin in your Java projects in the near future.

Because Kotlin works anywhere Java works, and can even be called from Java code (and vice-versa), this brings with it a massive opportunity for Java developers. Being able to work with both Java and Kotlin is going to give you a massive advantage over other programmers.

This course was designed to teach Java developers how to use Kotlin in the shortest possible time.

Sarah Ettritch, your course instructor, is an experienced Java and Kotlin developer, with many years of software development experience. She is uniquely qualified to teach you how to use this powerful and exciting language.

While you won't learn Android app development in this course, you will learn Kotlin, and also the key differences between Kotlin and Java.

There is an entire section dedicated to Java interoperability, which is vital for all Java developers to learn.

In addition, the Kotlin syntax is explored in detail.

Over sixteen hours of videos are included in the course, making it one of the most comprehensive courses on the language.

Now is the perfect time for you to learn Kotlin, while it's relatively new. It has been around for a while, but only now is it being thrust into the limelight.

It's absolutely vital for Java developers to learn Kotlin to maximize future career opportunities. Objective-C developers who failed to transition to Swift, or were too slow doing so, were left behind. Don't make the same mistake they did!

If you are ready to greatly increase your career prospects by adding Kotlin experience to your skills and knowledge, then sign up for the course today.

Who this course is for:

Java programmers wanting to learn Kotlin

Kotlin for Java Developers

What you'll learn

Explore related topics

Course content

Comprehensive Course Overview and Environment Setup for Kotlin10 lectures • 1hr 2min

Kotlin Fundamentals: Language Overview and Java Code Conversion5 lectures • 46min

Essential Kotlin Fundamentals: Grasping Key Differences from Java12 lectures • 1hr 34min

Kotlin Types and Null Safety: Mastering Data Types and Null Handling7 lectures • 1hr 42min

Object-Oriented Kotlin: Classes, Functions, and Class Inheritance19 lectures • 3hr 39min

Mastering Kotlin Loops, Conditionals: If, When, and Try/Catch as Expressions6 lectures • 1hr 36min

Kotlin Generics, Collections, and Functional Programming with Lambdas16 lectures • 4hr 2min

Kotlin File Input/Output (I/O) with Java Interoperability4 lectures • 31min

Java and Kotlin Interoperability: Mixing and Matching Code6 lectures • 1hr 33min