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I know the difference between pass by value and pass by reference. But while coding a logic I found it to be not completely clear.
Below is the code that I tested with a reference type arr, primitive int i and an object root of type Node(user defined).

static void recursiveFn(int[] arr, Node root, int i, int times) {
    if(times > 3)
        return;

    if(times == 2) {
        arr[0] = 1;
        i = 1;
        root = root.next;
    }

    times++;

    recursiveFn(arr, root, i, times);
    System.out.println(times+" - "+arr[0]+" "+i+" "+ root.data);
}

The output was:

4 - 1 1 1
3 - 1 1 1
2 - 1 0 0
1 - 1 0 0

The index zero of the array persists in the call stack while the control go backs to the previous recursive call - This is what pass by reference mean.
The int i produced its current value at respective function call.
I didn't understand why the root being an object didn't persists its value through out the recursive call.

Senthil Kumaran
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    Java is pass by value. The Node reference that you pass cannot be changed, but you can change its mutable state. – duffymo Nov 09 '20 at 11:39
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    “This is what pass by reference mean” — No. That’s a common misunderstanding. *Java does not have pass by reference at all.* – Konrad Rudolph Nov 09 '20 at 11:40

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