How is the type system structured in the Kotlin language?

In Kotlin, the type system is strict and static, meaning that variable types are known at compile time and cannot change during runtime. Key features:

• Primitive types and wrapper classes: Kotlin uses primitives (Int, Double, Boolean, etc.), but under the hood, they can be represented as objects.
• Nullable and Non-nullable types: By default, Kotlin types cannot hold null values. A special syntax with a question mark is used for nullable types, e.g., String?.
• Top-level types: All types inherit from the base class Any (similar to Object in Java), except nullable types, which inherit from Any?.
• Type parameters (Generics): Kotlin supports generics with constraints and variance (in, out).

Example of declaring a variable with a nullable type:

var name: String = "Ivan"
var nullableName: String? = null

Thus, Kotlin's type system helps avoid null-related errors and ensures type safety at compile time.