What objects do you know in Kotlin and how are they compiled?

• Data classes: automatically generate equals(), hashCode(), toString(), copy(), and other useful methods. They are compiled into regular classes with overridden methods.
• Enums: represent a fixed set of constants. They compile into classes with static fields for each element.
• Sealed classes: allow defining a restricted class hierarchy. They compile into regular classes with a private constructor and static instances for each subclass in the same file.
• Objects: Singleton objects. They compile into a class with a static instance field and a static initializer.

Example of Object in Kotlin:

object MySingleton {
    fun doSomething() {
        // Some logic
    }
}

Compilation into Java:

public final class MySingleton {
    public static final MySingleton INSTANCE;

    private MySingleton() {
    }

    public final void doSomething() {
        // Some logic
    }

    static {
        INSTANCE = new MySingleton();
    }
}