java - Modify an array passed as a method-parameter

Question

Suppose I have an int-array and I want to modify it. I know that I cannot assign a new array to array passed as parameter:

public static void main(String[] args)
{
    int[] temp_array = {1};
    method(temp_array);
    System.out.println(temp_array[0]); // prints 1
}
public static void method(int[] n)
{
    n = new int[]{2};
}

while I can modify it:

public static void main(String[] args)
{
    int[] temp_array = {1};
    method(temp_array);
    System.out.println(temp_array[0]); // prints 2
}
public static void method(int[] n)
{
    n[0] = 2;
}

Then, I tried to assign an arbitrary array to the array passed as parameter using clone():

public static void main(String[] args)
{
    int[] temp_array = {1};
    method(temp_array);
    System.out.println(temp_array[0]); // prints 1 ?!
}
public static void method(int[] n)
{
    int[] temp = new int[]{2};
    n = temp.clone();
}

Now, I wonder why it prints 1 in last example while I'm just copying the array with clone() which it's just copying the value not the reference. Could you please explain that for me?

---

EDIT: Is there a way to copy an array to object without changing the reference? I mean to make last example printing 2.

Answer 1

In your method

public static void method(int[] n)

n is another name for the array that way passed in. It points to the same place in memory as the original, which is an array of ints. If you change one of the values stored in that array, all names that point to it will see the change.

However, in the actual method

public static void method(int[] n) {
    int[] temp = new int[]{2};
    n = temp.clone();
}

You're creating a new array and then saying "the name 'n' now points at this, other array, not the one that was passed in". In effect, the name 'n' is no longer a name for the array that was passed in.