From a linked list to an array (Function)

I'm trying to give a function a list and make an array which contains the value of the nodes of the list (Not complicated). There it is:

public class MainClass {
public static int[] makeListIntoArray(Node<Integer> n) {
int[] arr1 = new int [countSizeOfList(n)];
for(int i = 0; i < countSizeOfList(n); i++) {
arr1[i] = n.getValue();
n = n.getNext();
}
return arr1;
}//EndOfFunction
public static int[] finalFunction2(Node<Integer> n) {
if(n == null) return ifListIsEmpty(n);
return makeListIntoArray(n);
}
public static int[] ifListIsEmpty(Node<Integer> n) {
Node<Integer> n2 = new Node<Integer>(999);
int[] arr1 = new int [countSizeOfList(n2)];
int i = 0;
arr1[i] = n2.getValue();
return arr1;
}
public static void main(String[] args) {
Node<Integer> n1 = new Node<Integer>(5);
Node<Integer> n2 = new Node<Integer>(4);
Node<Integer> n3 = new Node<Integer>(3);
Node<Integer> n4 = new Node<Integer>(5);
Node<Integer> n5 = new Node<Integer>(1);
n1.setNext(n2);
n2.setNext(n3);
n3.setNext(n4);
n4.setNext(n5);
System.out.println(finalFunction2(n1));
}//Main
}//Class

Thing is that it prints "[I@7960847b" beside of the actual array... fixes?

Any fixes?

If you want to insert a value into array then there should be an index especially a static one. You cannot simply assign it to arr1 like your do for primitive types.

For example, arr1[0] = n.getValue() is valid but not arr1 = n.getValue();

public static int[] makeListIntoArray(Node<Integer> n) {
int[] arr1 = new int [countSizeOfList(n)];
int idx=0;
while(n != null) {
arr1[idx++] = n.getValue();
n = n.getNext();
}
return arr1;
}//EndOfFunction

If you're using Java's built-in LinkedList data structure you can simply use the following to convert from LinkedList to array:

Integer[] array = list.toArray(new Integer[list.size()]);

So for the situation you're describing all you would need for the function is:

import java.util.LinkedList;

public class MainClass {
   public static int[] makeListIntoArray(LinkedList<Integer> list) {
       Integer[] arr = list.toArray(new Integer[list.size()]);
       int[] intArr = Arrays.stream(array).mapToInt(Integer::intValue).toArray();
       // Above line converts the wrapper Integer[] to int[] if you need that
       return intArr;
    }
}

You can find more info about LinkedList's toArray() method here.

If you want to keep the linked list but also want to access the elements in O(1), you can create an array of Nodes.

public class MainClass {
public static Node<Integer>[] makeListIntoArray(Node<Integer> n) {
Node<Integer>[] arr1 = new Node<Integer> [countSizeOfList(n)];
int i=0;
while(n != null) {
arr1[i] = n;
n = n.getNext();
++i;
}
return arr1;
}//EndOfFunction
}//Class