# Java Program to find sum and average of N numbers

In this post, we will write a two java program to Find Sum and Average of N numbers using an array. The first program finds the average of specified array elements. The second program takes the value of N and the numbers provided by the user and finds the average of them using an array.

To understand these programs you should have knowledge of following concepts:

• Java Arrays
• For loop

## How the program will work?

• First of all, accept an array.
• Now using loop we calculate the sum of elements of the array.
• Hence we have sum the divide it by array count to get average.

### Example:

1. Input:
2. Enter the array size: 5
3. Enter the 5 array elements
4. 6
5. 4
6. 5
7. 8
8. 6
9. Output:
10. Sum of 5 number is 29.
11. Average is 5.8.

## Example 1: Program to Calculate average using Array

In this program, we have a predefined value of array which will get add using for loop and then calculate the average by dividing the sum by count of array count.

```public class demo {
public static void main(String[] args) {
int arr[] = {5,6,48,6,78,20,65};
int len = arr.length;
double avg =0;

double sum = 0;

for (int i=0;i<len;i++){
sum += arr[i];
}
avg = sum/len;
System.out.println("Sum of "+len+" number in "+sum);
System.out.println("Average is "+avg);
}
}
```

### Output:

```Sum of 7 number in 228.0
Average is 32.57```

## Example 2: Program to Calculate the average of numbers entered by the user

In this program, we are using a Scanner to get the value of n and all the numbers from the user. First of all, take the array size for the user and then accept the array value using a loop. After that calculate the Sum of the array element using second for loop and divide it by array size to get the average of an array.

```import java.util.Scanner;

public class sum_of_array {
public static void main(String[] args) {

Scanner sc = new Scanner(System.in);
System.out.print("Enter the array size: ");
int len = sc.nextInt();
int arr[] = new int[len];
double sum = 0;
double avg = 0;

System.out.println("Enter the 5 array element");
for (int i=0;i<len;i++){
arr[i] = sc.nextInt();
}
for (int i=0;i<len;i++){
sum += arr[i];
}
avg = sum/len;
System.out.println("Sum of "+len+" number in "+sum);
System.out.println("Average is "+avg);
}
}```

### Output:

```Enter the array size: 5
Enter the 5 array element
45
48
65
35
48
Sum of 5 number in 241.0
Average is 48.2```