How to access to the inner ArrayList<Any> binded by an initial ArrayList of type <Any>

I am trying to access to the inner ArrayList<Any> in Kotlin... Please refer, herein. Is there a way? Many Thanks

fun main() {
	
	val y = ArrayList<Any>()
	for (i in 1..2){
		y.add(readln().split(' ').map {
			try {
				it.toInt()
			} catch (e: Exception) {
				it
			}
		})
	}
	
	println(y[0]::class.simpleName)
	println(y[1]::class.simpleName)
	println(y)
	y.forEach(::println)
	
}

I printed the class for y[0] and y[1] and the binding class y, all are of type ArrayList. However, accessing to the binding ArrayList is possible by way of lamda expression which shall retrieve the inner ArrayList. The inner list isn't accessible. Is there a way to do it?

Any assistance in this regard is appreciated

It is not possible for compiler to know that list is actually containing inner lists, since you declared your ArrayList as a list of elements of type Any.

However, you can make compiler check if list's element is actually an inner list.

y.forEach { it ->
    // Note that you cannot check for List<Int> since generic types are erased at runtime
    if (it is List<*>) { 
        println(it)
    }
}

The reason it is not possible without explicit check is that ArrayList<Any> is not invariant, meaning you cannot guarantee that object of type Any will have the functionality required from List since any object can be added to y.

Since you fill your list y only with lists, the simplest way to make the inner lists accessible as List would be to provide the type information that y is a list of Lists and not just a list of Anys:

val y = ArrayList<List<Any>>()
// now you can also iterate over the inner lists
y.forEach { it.forEach(::println) }