How to interleave two arrays into a new array

Creates a new List that holds the elements of list1 interleaved
with the elements of list2. For example, if list1 holds
<"over","river","through","woods"> and list2 holds <"the","and","the">,
then the new list should hold
<"over","the","river","and","through","the","woods">. Alternating between
list1 and list2. If one list is longer, the new list will contain all of
the extra values from the longer list at the end. For example, if list1
holds <"over","river","through","woods"> and list2 holds <"the","and">
then the new list should hold
<"over","the","river","and","through","woods">.

I suck at programing and can't see the logic on the last part of this assignment. Thank you for taking the time to look at this. //*

private static List<String> mergeLists(List<String> list1, List<String> list2) {
    long max = Math.max(((File) list1).length(),((File) list2).length());
    ArrayList<String> newlist = new ArrayList<String>();
    for (int i = 0; i < max; i++) {
        if (i < list1) {
            newlist.append(list1[i]);
            {
        if (i < list2) {
            newlist.append(list2[i]);
        }
    }


            return newlist; 
        }
    }
}

Solution

You definitely had the right idea, you almost got it. Guess you don't suck at programming that much :). You can use properties of a List for this, without casting to a File.

    public static void main(String[] args) {
        List<String> list1 = new ArrayList<>();
        list1.add("over");
        list1.add("river");
        list1.add("through");
        list1.add("woods");

        List<String> list2 = new ArrayList<>();
        list2.add("the");
        list2.add("and");

        mergeLists(list1, list2);
    }

    private static List<String> mergeLists(List<String> list1, List<String> list2) {

        // Get the max length of both arrays
        int max = Math.max(list1.size(), list2.size());

        // Initialize new list
        List<String> newList = new ArrayList<>();

        // add an element of the first list to the new list (if there are more elements)
        // and then add an element from the second list to the new list (if there are more elements)
        // and repeat...
        for (int i = 0; i < max; i++) {
            if (i < list1.size()) {
                newList.add(list1.get(i));
            }

            if (i < list2.size()) {
                newList.add(list2.get(i));
            }
        }

        System.out.println(newList);
        return newList;
    }