Kotlin: save null value in ArrayList?

I have created an ArrayList of nullable types, but when I try to add a null value to the list the null value doesn’t get added.
eg.

var intArray: ArrayList<Int?>? = null
intArray = ArrayList()

intArray.add(0)
intArray.add(null)
intArray.add(2)

This code returns an array with only 2 elements, ignoring the null value.
What I want to achieve is intArray.get(1) where it will return a null value.

Is there a way I can do that?

>Solution :

ArrayList is so old school, better you using – if possible – list:

   val xs = listOf<Int?>(1,2,null,4,5)

   println(xs)          // [1, 2, null, 4, 5]

   println(xs.get(2))   // null