C++ Program to Calculate Average Using Arrays

In this post, you will learn how to Calculate Average Using Arrays in C++ programming language.

This lesson will teach you how to Calculate Average Using Arrays, using mathematical operators, logical operator and the for loop statement using the C++ Language. Let’s look at the below source code.

How to Calculate Average Using Arrays?


Source Code

#include <iostream>
using namespace std;
int main() 
   int n, i;
   float sum = 0.0, avg;
   float num[] = {12, 76, 23, 9, 5};
   n = sizeof(num) / sizeof(num[0]);
   for(i = 0; i < n; i++)
   sum += num[i];
   avg = sum / n;
   cout<<"Average of all array elements is "<<avg;
   return 0;


Average of all array elements is 25

The statements #include<iostream>, using namespace std, int main are the main factors that support the function of the source code.

Now we can look into the working and layout of the code’s function.

  1. Declare the variables n, i as integers and sum, avg, num as float values. The float datatype is used when decimal values are used or displayed in the process.
  2. Assign the float variable as follows :
    float sum = 0.0; float num[] = {12, 76, 23, 9, 5};The variable sum is assigned to 0.0 and the variable num is assigned with the array of numbers for which the average is to be calculated.
  3. In this code we insert the input values in the code, rather than getting them from the user. The [ ] is used to specify that the variable is to hold an array value.
  4. Calculate the value of by using the mathematical function n = sizeof(num) / sizeof(num[0])
  5. Declare a for loop with the condition (i = 0; i < n; i++), followed by the a logical function with the AND addition operator to add the values of the array.
  6. Next find the average of the values of the array using the mathematical function avg = sum / n.
  7. Use the output function cout to display the output statement and the Average of the array of numbers.