great article, just one small correction: You state that

null

has no type, but it’s type is

Nothing?

. You mention that later by saying that

Nothing?

as a return type forces you to return

null

. You can also verify this with this code

val foo = null
println(::foo)

thanks! but i’m not the author 😅

Another thing I noticed is in this snippet:

//Java
public static Consumer<Integer> printNum = x -> System.out.println("Num " + x);

//Kotlin
fun callMe(block: (Int) -> Unit): Unit = (1..100).forEach(block)

fun main(){
    callMe { Lambdas.printNum } //it works fine
}

nothing would happen because he's not actually passing in the function (and as far as I understand it won't compile). I believe the following was actually meant

callMe(Lambdas::printNum) // it works fine