Hands-On Object-Oriented Programming with Kotlin

Hierarchical inheritance

A situation in which a parent class is inherited by many subclasses is called hierarchical inheritance. This is shown in the following diagram, where A is a parent class and B, C, and D are child classes. In this inheritance model, two or more classes are derived from the parent class:

Create a superclass, Person, and two derived classes, Student and Employee:

open class Person (val fName: String, var lName: String, var pAge: Int, val ID : String) {    fun speak() {        println("My name is $fName $lName, my id is $ID and age is $pAge")    }    fun greet() {        println("Hi How are you...")    }}class Student(fName: String, lName: String, ...