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Kuidas erinevad Kotlin'i tüübid Java tüüpidest?

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

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

Kotlin has data classes (data class), which 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 object creation syntax does not require the new keyword.

Primitive types in Kotlin are built-in and are compiled to Java primitives when necessary, unlike Java's separate primitive types.

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+)
Object creation Without new With new
Primitive types Built-in, compiled to Java primitives Separate types (int, float, etc.)