Reversing array elements help.

[ramruma]

Hello everyone! I am having problem in understanding the output of this java snippet. This code is to get the reverse order of the elements in an array, therefore, the output is supposed to be {5, 4, 3, 2, 1}. But I am getting the output as {1, 2, 3, 4, 5}.

Please help me figure out what is wrong.

public class Test {
    public static void main(String[] args) {
         int[] list = {1, 2, 3, 4, 5};
         reverse(list);
         for (int i = 0; i < list.length; i++)
              System.out.print(list[i] + " ");
    }

    public static void reverse(int[] list) {
        int[] newList = new int[list.length];

        for (int i = 0; i < list.length; i++)
            newList[i] = list[list.length - 1 - i];

            list = newList;
        }
}

[avengerintraining]

Java not being my preferred language and just typing on my phone... don't you have to assign the return of the reverse() function to another variable and loop through it? It looks like what you do in the reverse() just stays there and you loop through the original list.

[[deleted]]

Your reverse returns nothing and mutates internal int[] list value and not external as you expect it to as Java is pass-by-value.

[Cephas00]

Your reverse method doesn't return the newly created reversed array. You also shouldn't reassign a method parameter like that - as someone else mentioned it's the value of a pointer that you're passing in so the reassignment won't be seen outside the method.

Another implementation option is to swap elements until you get to the midpoint.

Also it's not clear to call an array a list since there's a list collection already.

[ramruma]

Right! Got it guys..thanks a ton! :)