How to implement inheritance for classes in Kotlin?

In Kotlin, to implement inheritance, a class must be declared with the open keyword to allow inheritance from it (by default, all classes are final). The inherited class is specified with a colon after the class name.

Example:

open class Animal(val name: String) {
    open fun sound() {
        println("Some sound")
    }
}

class Dog(name: String) : Animal(name) {
    override fun sound() {
        println("Bark")
    }
}

fun main() {
    val dog = Dog("Buddy")
    dog.sound()  // Outputs: Bark
}

Here, Animal is the base class, Dog is the subclass that overrides the sound method. The override keyword is mandatory when overriding methods.