Kotlin Programming Cookbook

How to do it...

Now we will see how to work with a nested class in the following steps:

1. Let's try an example of a nested class in Kotlin:

fun main(args: Array<String>) {    var a1 = outCl()    a1.printAB()    outCl.inCl().printB()}class outCl {var a = 6    fun printAB () {    var b_ = inCl().b    println ("a = $a and b = $b_ from inside outCl")} class inCl {    var b = "9"        fun printB() {            println ("b = $b from inside inCl")        }    }}

Here's the output:

a = 6 and b = 9 from inside outClb = 9 from inside inCl

2. Now, let's try an example of the inner class. To declare a nested class as inner, we use the inner keyword. An inner class can access members of the outer class, as they carry a reference to the outer class:

fun main(args: Array<String>) {    var a = outCl() a.printAB() ...