Mention the structural expressions in Kotlin?

In Kotlin, there are several structural expressions that can be used to define the structure of a program. Some of the most common structural expressions in Kotlin include: Functions: Functions are a fundamental building block of Kotlin programs. They are used to encapsulate reusable code and can be defined at the top level or inside classes and objects. Classes: Classes are used to define custom data types in Kotlin. They can contain properties, methods, and other members. Interfaces: Interfaces are used to define contracts that a class must implement. They can contain property declarations, method signatures, and default implementations. Objects: Objects are used to define singletons or objects that have a specific behavior. They can be used to define utility functions or stateless objects. Enums: Enums are used to define a fixed set of values that a variable can take. They are commonly used to represent categories or options. Annotations: Annotations are used to provide metadata about program elements, such as classes, functions, and properties. They are used by tools and frameworks to generate code or perform other tasks. These structural expressions in Kotlin provide a flexible and powerful way to define the structure of a program, making it easier to write maintainable and scalable code.