Nested and Inner Classes

                  class Outer {
    private val bar: Int = 1
    class Nested {
        fun foo() = 2
    }
}
​
val demo = Outer.Nested().foo() // == 2
                

                    class Outer {
    private let bar: Int = 1
    class Nested {
        func foo() = 2
    }
}
​
let demo = Outer.Nested().foo() // == 2
                  

                  interface OuterInterface {
    class InnerClass
    interface InnerInterface
}
​
class OuterClass {
    class InnerClass
    interface InnerInterface
}
                

                    interface OuterInterface {
    class InnerClass
    interface InnerInterface
}
​
class OuterClass {
    class InnerClass
    interface InnerInterface
}
                  

Inner classes

                  class Outer {
    private val bar: Int = 1
    inner class Inner {
        fun foo() = bar
    }
}
​
val demo = Outer().Inner().foo() // == 1
                

                    class Outer {
    private let bar: Int = 1
    inner class Inner {
        func foo() = bar
    }
}
​
let demo = Outer().Inner().foo() // == 1
                  

Anonymous inner classes

                  window.addMouseListener(object : MouseAdapter() {
​
    override fun mouseClicked(e: MouseEvent) { ... }
​
    override fun mouseEntered(e: MouseEvent) { ... }
})
                

                    window.addMouseListener(object : MouseAdapter() {
​
    override func mouseClicked(e: MouseEvent) { ... }
​
    override func mouseEntered(e: MouseEvent) { ... }
})
                  

                  val listener = ActionListener { println("clicked") }
                

                    let listener = ActionListener { print("clicked") }