public class main
{
  public static int arraySum(int[] arr)
  {
    int result = 0;
    for (int i = 0; i < arr.length; i++)
    {
      result += arr[i];
    }
    return result;
  }
  public static int arraySumBetter(int [] a)
  {
    int result = 0;
    for (int value : a)
    {
      result += value;
    }
    return result;
  }

  public static void main(String [] args)
  {
    double[] a ={0,2,3,1,0.56};
    System.out.format("%.1f", (double) arraySumBetter(a));
  }
}

typed.java:25: error: incompatible types: double[] cannot be converted to int[]
    System.out.format("%.1f", (double) arraySumBetter(a));
                                                      ^
Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output
1 error

System.out.format("%.1f", (double) arraySumBetter(a));
                               ^ remove

public static int arraySumBetter(double[] a)
  {
    double result = 0;
    for (double value : a)
    {
      result += value;
    }
    return result;
  }