Java Program to Calculate Average Using Arrays

A quick and practical guide to find and to calculate the average of numbers in array using java language.

1. Overview

In this article, you'll learn how to calculate the average of numbers using arrays. 

You should know the basic concepts of a java programming language such as Arrays and forEach loops.

We'll see the two programs on this. The first one is to iterate the arrays using for each loop and find the average.

In the second approach, you will read array values from the user.

Let us jump into the example programs.

2. Example 1 to calculate the average using arrays

First, create an array with values and run. the for loop to find the sum of all the elements of the array.

Finally, divide the sum with the length of the array to get the average of numbers.

package com.javaprogramto.programs.arrays.average;

public class ArrayAverage {

	public static void main(String[] args) {

		// create an array
		int[] array = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 };

		// getting array length
		int length = array.length;

		// default sium value.
		int sum = 0;

		// sum of all values in array using for loop
		for (int i = 0; i < array.length; i++) {
			sum += array[i];
		}

		double average = sum / length;
		
		System.out.println("Average of array : "+average);

	}

}

Output:

Average of array : 6.0

3. Example 2 to find the average from user inputted numbers

Next, let us read the input array numbers from the user using the Scanner class.

Scanner Example to add two numbers

import java.util.Scanner;

public class ArrayAverageUserInput {

	public static void main(String[] args) {

		// reading the array size.
		Scanner s = new Scanner(System.in);

		System.out.println("Enter array size: ");
		int size = s.nextInt();
		// create an array
		int[] array = new int[size];

		// reading values from user keyboard
		System.out.println("Enter array values :  ");
		for (int i = 0; i < size; i++) {
			int value = s.nextInt();
			array[i] = value;

		}

		// getting array length
		int length = array.length;

		// default sium value.
		int sum = 0;

		// sum of all values in array using for loop
		for (int i = 0; i < array.length; i++) {
			sum += array[i];
		}

		double average = sum / length;

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

	}

}

Output:

Enter array size: 
5
Enter array values :  
12
23
34
45
56
Average of array : 34.0

4. Conclusion

In this article, you've seen how to calculate the average number in an array.

All examples shown are in GitHub.

Average