# 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**.

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: ` `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**.

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);