Create a method in Java that returns an arrayList of integers:

public static ArrayList<Integer> getIntList(){

    ArrayList<Integer> integers = new ArrayList<>();
    integers.add(1);integers.add(2);integers.add(3);

    return integers;
}

getIntList returns an array that contains three elements. Call this function in Kotlin to access the list and add more elements in it:

var list = CallJava.getIntList()
//var list: ArrayList<Int> = CallJava.getIntList()

list.add(4)
for (element in list) {
   println("Element $element")
}

CallJava.getIntList() returns ArrayList, which can be assigned to a list type of variables. We explicitly declare the type of the list by using the ArrayList<Int> name:

var list: ArrayList<Int> = CallJava.getIntList()

Alternatively, we can directly assign a list to the variable and Kotlin will figure out the list type by itself:

var list = CallJava.getIntList()

We can treat this as a normal immutable list and we can add or remove elements.