OddElementSum.java

package Lesson3.KeyPoint2;

/**
 * Created by Юрий on 18.12.2015.
 */
public class OddElementSum {
    public static void main(String[] args) {

        int[] arr = {1, 2, 3, 4, 5};
        int[] arr1 = {1, 2};
        int[] arr2 = {1};
        int[] arr4 = null;

        System.out.println(oddElementSum(arr));
        System.out.println(oddElementSum(arr1));
        System.out.println(oddElementSum(arr2));
        System.out.println(oddElementSum(arr4));
    }

    static long oddElementSum(int data[]) {
        if (data != null && data.length >= 2) {
            int sum = 0;
            for (int i = 1; i < data.length; i += 2) {
                sum += data[i];
            }
            return sum;
        }
        return -1;
    }
}