sumOfAnArray.java

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 */
package javaapplication9;

/**
 *
 * @author f023507i
 */
public class JavaApplication9
{

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args)
    {
        int[] mainArr = null;
        int[] mainArr2 = {1,2,3,4,5,6};
        int[] mainArr3 = {5};
        int[] mainArr4 = {};
        System.out.println(SumArr(mainArr));
        System.out.println(SumArr(mainArr2));
        System.out.println(SumArr(mainArr3));
        System.out.println(SumArr(mainArr4));

        // TODO code application logic here
    }

    public static int SumArr(int[] arr)
    {
        if (arr == null || arr.length == 0)
        {
            return 0;
        }
        if (arr.length == 1)
        {
            return arr[0];
        }
        return SumArrWithSize(arr, arr.length, 0);
    }

    public static int SumArrWithSize(int[] arr, int size, int accum)
    {

        if (size == 0)
        {
            return accum;
        }

        accum += arr[size - 1];
        size--;
        return SumArrWithSize(arr, size, accum);

    }

}