Kotlin Inheritance

The inheritance in Kotlin language is almost the same as Java with a slight modification. Here is the general systax of Kotlin inheritance in a simple example:

// Base parent (Super class)
open class Person {
}

// Childe  class (Sub class)
class Students: Person() {
}

Here is an example with constructor:

open   class Person(val name:String,val age:Int){
    }

//Inheritance for Employee from Person class
class Employee(name:String,age:Int, val salary:Int):Person(name,age){    
}

Here is the complete code with intanciation :

open   class Person(val name:String,val age:Int){
    }
//Inheritance for Employee from Person class
class Employee(name:String,age:Int, val salary:Int):Person(name,age){   
}
fun main(args: Array< String >) {
    //Create object Person P
    var E=Employee("Richard",35,28000)
    println("Empoyee name is : " + E.name)
    println("The Employee's age is : " + E.age)
    println("The Employee's salary is : " + E.salary)
}

Inheritance from the methods of the super class.
Here’s an example of a child class: Rectangle that inherits the perimeter method from the super class  Parallelogram:

open   class Parallelogram(val side1:Int,val side2:Int){
    fun perimeter():Int{
        return 2*(this.side1+this.side2)
    }
    }
//Inheritance for Employee from Person class
class Rectangle(side1:Int,side2:Int):Parallelogram(side1,side2){   
}
fun main(args: Array< String >) {
    //Create object Rectangle
    var R=Rectangle(10,7)
  
    println("The perimeter of rectangle R is : " + R.perimeter())
}