Finding the average of all elements in an array.

Here’s a Java program that calculates the average of all elements in an array:

public class AverageCalculator {

    public static void main(String[] args) {

        int[] numbers = { 5, 10, 15, 20, 25 };

        double average = calculateAverage(numbers);

        System.out.println("Average: " + average);

    }

    public static double calculateAverage(int[] array) {

        int sum = 0;

        for (int number : array) {

            sum += number;

        }

        return (double) sum / array.length;
    }

}

In this program, we have a method called `calculateAverage` that takes an integer array as input and returns the average as a `double`. It calculates the sum of all elements in the array by iterating over each element using a for-each loop. Finally, it divides the sum by the length of the array to obtain the average.

In the `main` method, we create an array of numbers `{ 5, 10, 15, 20, 25 }`, and then we call the `calculateAverage` method with this array as an argument. The average is stored in the `average` variable, which is then printed to the console.