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.
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 | 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:
1 | 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
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 | 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:
1 2 3 4 5 6 7 8 9 | Enter array size: 5Enter array values : 1223344556Average 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.
Published on Java Code Geeks with permission by Venkatesh Nukala, partner at our JCG program. See the original article here: Java Program to Calculate Average Using Arrays Opinions expressed by Java Code Geeks contributors are their own. |
There is a mistake in both programs. If You divide in Java two integers, You will get an integer result. To correct it cast at least one of the operands to double, like this:double average = (double)sum/length;
Better method:
double average = arrray.stream()
.mapToDouble(Integer::doubleValue)
.average()
.orElse(0.0);