Route from Java to Kotlin

What if you could eliminate NullPointerExceptions at compile time? This session shows Java developers how to write safer, more concise code with Kotlin.

#1about 3 minutes

Introduction to Kotlin and its Java interoperability

Kotlin is a mature, multi-paradigm language that is fully interoperable with Java libraries and is used in production by major companies.

#2about 5 minutes

Defining variables and working with strings in Kotlin

Learn Kotlin's basic syntax for variables using `var` and `val`, how type inference simplifies code, and how to use string templates for concatenation.

#3about 5 minutes

Using expressions instead of statements for cleaner code

Kotlin treats control flow structures like `if-else`, `try-catch`, and the powerful `when` block as expressions that return a value, eliminating temporary variables.

#4about 7 minutes

Writing concise functions with named and default arguments

Simplify function definitions using expression bodies for single-line returns and avoid method overloading by using named and default arguments.

#5about 5 minutes

Iterating with loops, ranges, and collections

Use Kotlin's intuitive syntax for `for` loops with ranges (`..`, `until`, `downTo`) and iterate over immutable lists with index destructuring.

#6about 8 minutes

Achieving null safety with nullable types and operators

Prevent null pointer exceptions by using Kotlin's type system, which distinguishes between nullable and non-nullable types, along with the safe call (`?.`) and Elvis (`?:`) operators.

#7about 5 minutes

Applying functional programming with lambdas and collections

Define and use lambdas with a concise syntax, leveraging the implicit `it` parameter and trailing lambda syntax for clean collection operations like `filter`.

#8about 4 minutes

Extending existing classes with extension functions

Add new functionality to any existing class, including final Java classes, without using inheritance by defining extension functions.

#9about 4 minutes

Understanding classes, data classes, and operator overloading

Use `data class` to automatically generate `equals`, `hashCode`, and `toString`, and learn how operator overloading can create more readable code for types like `BigDecimal`.

#10about 11 minutes

Audience Q&A on Kotlin features and learning resources

The speaker answers audience questions about Kotlin's relationship to Scala, the potential dangers of operator overloading, and recommended learning resources.