Java Arrays pass by reference [duplicate]

Question

I wonder why the output is still 1,2,3,4,5, since if I change a value in doIt (for example : z[0] = 10), the array is changed.

public class Main 
{
    public static void main(String[] args) {
        int[] array = {0,1,2,3,4,5};
        testIt.doIt(array);

        for(int i=0;i<array.length;i++){
            System.out.println(array[i]);
        }
    }
}

class testIt
{
    public static void doIt(int [] z){
        z = null    
    }
}

Read this stackoverflow.com/questions/40480/…

René Link
– René Link

2014-10-22 06:39:50 +00:00
Commented Oct 22, 2014 at 6:39 — René Link
– René Link, Commented Oct 22, 2014 at 6:39

Ruchira Gayan Ranaweera · Accepted Answer · 2014-10-22 06:54:30Z

1

Here

doIt is passed a copy of the array reference and can't change the original reference and make no difference to original array.

edited Oct 22, 2014 at 6:54

answered Oct 22, 2014 at 6:40

Ruchira Gayan Ranaweera

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Comments

Eran · Accepted Answer · 2014-10-22 06:39:37Z

1

doIt is passed a copy of the array reference, so it can't change the original reference (stored in the array variable). It can only change the state of the object referred by this reference. Therefore setting z to null inside doIt makes no difference outside the method.

answered Oct 22, 2014 at 6:39

Eran

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