Computing the average value of an array of numbers (in this case integers) can be implemented in two simple steps:

1. Compute the sum of the elements from the array.
2. Divide this sum by the length of the array.

In code lines, we have the following:

public static double average(int[] arr) {

  return sum(arr) / arr.length;
}

public static double sum(int[] arr) {

  double sum = 0;

  for (int elem: arr) {
    sum += elem;
  }

  return sum;
}

The average of our integers array is 2.0:

double avg = MathArrays.average(integers);

In Java 8 functional style, the solution to this problem entails a single line of code:

double avg = Arrays.stream(integers).average().getAsDouble();