Question

I wrote code to reverse an integer array. Code is as shown below:

public class ReverseArray {

    public static void main(String[] args) {
        try {
            int[] arr = new int[5];
            arr[0] = 1;
            arr[1] = 2;
            arr[2] = 3;
            arr[3] = 4;
            arr[4] = 5;
            for (int i = 0; i <= arr.length/2; i++)
                int temp = arr[0];
                arr[0] = arr[arr.length - i - 1];
                arr[arr.length - i - 1] = temp;
            }
            System.out.println(arr);

        } catch (Exception e) {
            System.out.println(e);
        }
    }
}

But it’s not reversing the array.. I’m getting following output.

 [I@3bad086a

I don’t see anything wrong with my logic.

Answer 1

That is printing out the reference to the array.
If you print out the array one element at a time, you will see the reversed array.

EDIT:
Two more points.

1. You’re using arr[0] when you intend to use arr[i].
2. More insidious: you’re iterating too much. You only need to iterate until arr.length / 2. Since this is a homework question, I leave it to you to find out why; try printing out the intermediate results and explaining them.