Java Records vs Kotlin Data Classes

Question

Java 14 offers a new feature called records, helping to create JavaBeans. What is the difference between Kotlin's data classes and Java records?

Answer 1

This is a great article about all those differences.

In summary:

Similarities

• generated methods: equals, hashCode, toString
• generated constructor
• generated getters (but Kotlin getter is called o.name, while Java uses o.name())
• can modify the canonical constructor
• can add additional methods

Differences

Kotlin's data classes support many other little things:

data class (Kotlin)	record (Java)
copy method for easier object creation	no copy method
variables can be var or val	variables can only be final
can inherit from other non-data classes	no inheritance
can define non-constructor mutable variables	can define only static variables

Both are great for reducing the code bloat.