Program for average of an array (Iterative and Recursive)

Given an array, the task is to find average of that array. Average is the sum of array elements divided by the number of elements.

Examples :

Input : arr[] = {1, 2, 3, 4, 5}
Output : 3
Sum of the elements is 1+2+3+4+5 = 15 
and total number of elements is 5.
So average is 15/5 = 3

Input : arr[] = {5, 3, 6, 7, 5, 3}
Output : 4.83333
Sum of the elements is 5+3+6+7+5+3 = 29
and total number of elements is 6.
So average is 29/6 = 4.83333.

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Iterative:
Iterative program is easy. We need to find sum and divide sum by total number of elements.

C++

// C++ program to calculate average of array elements 
#include <iostream> 
using namespace std; 
  
// Function that return average of an array. 
double average(int a[], int n) 
{ 
    // Find sum of array element 
    int sum = 0; 
    for (int i=0; i<n; i++) 
       sum += a[i]; 
  
    return sum/n; 
} 
  
// Driver code 
int main() 
{ 
    int arr[] = {10, 2, 3, 4, 5, 6, 7, 8, 9}; 
    int n = sizeof(arr)/sizeof(arr[0]); 
  
    cout << average(arr, n) << endl; 
    return 0; 
} 

Java

// Java program to calculate average of array elements 
class GFG { 
      
    // Function that return average of an array. 
    static double average(int a[], int n) 
    { 
          
        // Find sum of array element 
        int sum = 0; 
          
        for (int i = 0; i < n; i++) 
            sum += a[i]; 
      
        return sum / n; 
    } 
      
    //driver code 
    public static void main (String[] args) 
    { 
          
        int arr[] = {10, 2, 3, 4, 5, 6, 7, 8, 9}; 
        int n = arr.length; 
      
        System.out.println(average(arr, n)); 
    } 
} 
  
// This code is contributed by Anant Agarwal. 

Python3

# Python3 code to calculate  
# average of array elements 
  
# Function that return  
# average of an array. 
def average( a , n ): 
  
    # Find sum of array element 
    sum = 0
    for i in range(n): 
        sum += a[i] 
      
    return sum/n; 
  
# Driver code 
arr = [10, 2, 3, 4, 5, 6, 7, 8, 9] 
n = len(arr) 
print(average(arr, n)) 
  
# This code is contrbuted by "Shard_Bhardwaj". 

C#

// C# program to calculate average of 
// array elements 
using System; 
class GFG { 
      
    // Function that return average of  
    // an array. 
    static double average(int []a, int n) 
    { 
          
        // Find sum of array element 
        int sum = 0; 
          
        for (int i = 0; i < n; i++) 
            sum += a[i]; 
      
        return sum / n; 
    } 
      
    // Driver code 
    public static void Main () 
    { 
          
        int []arr = {10, 2, 3, 4, 5, 6,  
                                7, 8, 9}; 
        int n = arr.Length; 
      
        Console.Write(average(arr, n)); 
    } 
} 
  
// This code is contributed by nitin mittal. 

PHP

<?php 
// PHP program to calculate average 
// of array elements 
  
// Function that return average of 
// an array. 
function average( $a, $n) 
{ 
      
    // Find sum of array element 
    $sum = 0; 
    for ( $i = 0; $i < $n; $i++) 
        $sum += $a[$i]; 
  
    return $sum / $n; 
} 
  
// Driver code 
    $arr = array(10, 2, 3, 4, 5, 
                        6, 7, 8, 9); 
    $n = count($arr); 
  
    echo average($arr, $n); 
  
// This code is contributed by anuj_67. 
?> 

Output:

Recursive:
The idea is to pass index of element as an additional parameter and recursively compute sum. After computing sum, divide the sum by n.

C++

// C++ program to calculate average of array elements 
#include <iostream> 
using namespace std; 
  
// Recursively computes average of a[] 
double avgRec(int a[], int i, int n) 
{ 
    // Last element 
    if (i == n-1) 
        return a[i]; 
  
    // When index is 0, divide sum computed so 
    // far by n. 
    if (i == 0) 
        return ((a[i] + avgRec(a, i+1, n))/n); 
  
    // Compute sum 
    return (a[i] + avgRec(a, i+1, n)); 
} 
  
// Function that return average of an array. 
double average(int a[], int n) 
{ 
     return avgRec(a, 0, n); 
} 
  
// Driver code 
int main() 
{ 
    int arr[] = {10, 2, 3, 4, 5, 6, 7, 8, 9}; 
    int n = sizeof(arr)/sizeof(arr[0]); 
  
    cout << average(arr, n) << endl; 
    return 0; 
} 

Java

// Java program to calculate average  
// of array elements 
  
class CalcAvg 
{ 
    // Recursively computes average of a[] 
    static double avgRec(int a[], int i, int n) 
    { 
        // Last element 
        if (i == n-1) 
            return a[i]; 
       
        // When index is 0, divide sum computed so 
        // far by n. 
        if (i == 0) 
            return ((a[i] + avgRec(a, i+1, n))/n); 
       
        // Compute sum 
        return (a[i] + avgRec(a, i+1, n)); 
    } 
       
    // Function that return average of an array. 
    static double average(int a[], int n) 
    { 
         return avgRec(a, 0, n); 
    } 
      
    // main function 
    public static void main (String[] args)  
    { 
        int arr[] = {10, 2, 3, 4, 5, 6, 7, 8, 9}; 
        int n = arr.length; 
       
        System.out.println(average(arr, n)); 
    } 
} 

Python3

# Python3 code to calculate 
# average of array elements 
  
# Recursively computes average of a[] 
def avgRec( a , i , n ): 
      
    # Last element 
    if i == n-1: 
        return a[i] 
      
    # When index is 0, divide sum 
    # computed so far by n. 
    if i == 0: 
        return ((a[i] + avgRec(a, i+1, n)) / n) 
      
    # Compute sum 
    return (a[i] + avgRec(a, i+1, n)) 
  
# Function that return  
# average of an array. 
def average(a, n): 
    return avgRec(a, 0, n) 
  
# Driver code 
arr = [10, 2, 3, 4, 5, 6, 7, 8, 9] 
n = len(arr) 
print(average(arr, n)) 
  
# This code is contributed by "Sharad_Bhardwaj". 

C#

// C# program to calculate average  
// of array elements 
using System; 
  
class GFG { 
      
    // Recursively computes average of a[] 
    static double avgRec(int []a, int i, int n) 
    { 
          
        // Last element 
        if (i == n-1) 
            return a[i]; 
      
        // When index is 0, divide sum  
        // computed so far by n. 
        if (i == 0) 
            return ((a[i] + avgRec(a, i+1, n))/n); 
      
        // Compute sum 
        return (a[i] + avgRec(a, i+1, n)); 
    } 
      
    // Function that return average of an array. 
    static double average(int []a, int n) 
    { 
        return avgRec(a, 0, n); 
    } 
      
    // main function 
    public static void Main ()  
    { 
        int []arr = {10, 2, 3, 4, 5, 6, 7, 8, 9}; 
        int n = arr.Length; 
      
        Console.Write(average(arr, n)); 
    } 
} 
  
// This code is contributed by Smitha. 

PHP

<?php 
// PHP program to calculate  
// average of array elements 
  
// Recursively computes  
// average of a[] 
function avgRec($a, $i, $n) 
{ 
    // Last element 
    if ($i == $n - 1) 
        return $a[$i]; 
  
    // When index is 0, divide  
    // sum computed so far by n. 
    if ($i == 0) 
        return (($a[$i] +  
                 avgRec($a, $i +  
                         1, $n)) / $n); 
  
    // Compute sum 
    return ($a[$i] +  
            avgRec($a, $i + 1, $n)); 
} 
  
// Function that return  
// average of an array. 
function average($a, $n) 
{ 
    return avgRec($a, 0, $n); 
} 
  
// Driver code 
$arr = array(10, 2, 3, 4,  
             5, 6, 7, 8, 9); 
$n = sizeof($arr); 
  
echo average($arr, $n) ; 
  
// This code is contributed by Anuj_67 
?> 

Output :

Related Article :
Average of a stream of numbers

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My Personal Notes

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

C++

Java

Python3

C#

PHP

C++

Java

Python3

C#

PHP

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