How do types in Kotlin differ from types in Java?

Kotlin has null-safety, which allows explicitly indicating whether a variable can contain null. In Java, all reference types can be null by default.

Kotlin supports extension functions and properties, enabling adding new capabilities to existing classes without inheritance or using the Decorator pattern.

Kotlin has data classes (data class) that automatically generate equals(), hashCode(), toString(), copy(), and destructuring components.

Kotlin supports covariance and contravariance in generics using the keywords out and in. In Java, this is done with wildcards (? extends T, ? super T).

Kotlin has smart casts, which automatically cast the type of a variable after a type check (if (x is String)).

Kotlin supports higher-order functions and lambda expressions, simplifying functional programming.

Kotlin uses syntax for creating object instances without the new keyword.

Kotlin has differences in primitive types: they are not separate classes but built-in language types that compile to Java primitives when necessary.

Feature	Kotlin	Java
Null-safety	Built into the type system	Uses @Nullable
Extensions	Supported	Not supported
Data classes	data class	Generated manually/IDE
Covariance/Contravariance	out, in	Wildcards (? extends, ? super)
Smart casts	Automatic after check	Requires explicit cast
Functions	Higher-order, lambda	Anonymous/lambda expressions (Java 8 and above)
Object creation	Without new	With new
Primitive types	Built-in, compile to Java primitives	Separate types (int, float, etc.)