What type of data can a class property hold?

A class property in Kotlin can hold both primitive and reference types. This capability is fundamental to Kotlin's design, as it allows for a diverse range of data to be stored in class properties.

Primitive types include values like integers, floating-point numbers, and booleans, which are basic data types. Reference types encompass more complex structures such as objects and arrays. In Kotlin, primitive types can be treated as instances of their corresponding wrapper classes, which allows for enhanced functionality. For example, an Int can be utilized directly in a class property, and you can also define properties that hold an object of a custom class or a built-in class like ArrayList.

This flexibility supports a versatile approach to programming, enabling developers to create classes that can encapsulate both simple data and more complex entities, making the code more modular and organized.