# Kotlin and Java interoperability: Types

DevFeed: [Kotlin and Java interoperability: Types](<https://devfeed.tech/articles/kotlin-and-java-interoperability-types-39201.md>)

Original publisher: [Read original article](<https://kt.academy/article/ak-java-interop-1>)

Published: 2023-07-31T00:15:00Z

Content type: tutorial

Language: en

Sources: [Kt. Academy](<https://devfeed.tech/sources/kt-academy.md>)

Topics: [interoperability](<https://devfeed.tech/topics/interoperability.md>), [Kotlin](<https://devfeed.tech/topics/kotlin.md>), [Java](<https://devfeed.tech/topics/java.md>), [Programming](<https://devfeed.tech/topics/programming.md>)

Tags: [interoperability](<https://devfeed.tech/tags/interoperability.md>), [java](<https://devfeed.tech/tags/java.md>), [kotlin](<https://devfeed.tech/tags/kotlin.md>), [types](<https://devfeed.tech/tags/types.md>), [workshop-learning-programming](<https://devfeed.tech/tags/workshop-learning-programming.md>)

## AI overview

This tutorial explains type interoperability between Kotlin and Java on the JVM, focusing on nullability annotations, platform types, type mapping, and the safety risks of treating Java values as non-null.

## Source excerpt

See surprising transitions that happens on types when you interoperate between Kotlin and Java.