Thread: sum an array using function

Hello,

I created the following code:

Code:

// Headers and Other Technical Items

#include <iostream>
#include <fstream>         // For file I/O 
#include <iomanip>         // For setw()
using namespace std;

// Function Prototypes

int  count_file_values(char input_filename[]);
void load_array_from_file(char input_filename[], int things[], int array_size);
void display_array(int things[], int array_size);
int  sum_array(int things[], int array_size);
void pause(void);

// Variables
 
char     data_filename[]  = "C:\Cpp_Source_Code_Files\Chapter_19\Demo_Farm_Acres_Input";

//******************************************************
// main
//******************************************************

int main(void)
  {
  int record_count = count_file_values(data_filename);
  int acres[record_count];
  load_array_from_file(data_filename, acres, record_count);
  cout << "The individual farm acerages are: \n";
  display_array(acres, record_count);
  cout << "\n\nThe total acerage is: " << sum_array(acres, record_count);
  pause();

  return 0;
  }

//******************************************************
// count_file_values
//******************************************************

int count_file_values(char input_filename[])
  {
  fstream  inData;           // device token for the input stream
  double   next_value;
  int      number_of_values = 0;
  
  inData.open(input_filename, ios::in);        //Open input file
  if (!inData)
    {
    cout << "\n\nError opening input data file: " << input_filename << "\n\n";
    pause();
    exit(EXIT_FAILURE);
    }
  // Get data values and count them

  while (inData >> next_value)
    {
    number_of_values++;
    }

  // Close the files
  inData.close();                              //Close input file

  return number_of_values;
  }

//******************************************************
// load_array_from_file
//******************************************************

void load_array_from_file(char input_filename[], int things[], int array_size)
  {
  fstream  inData;           // device token for the input stream

  inData.open(input_filename, ios::in);        //Open input file
  if (!inData)
    {
    cout << "\n\nError opening input data file: " << input_filename << "\n\n";
    pause();
    exit(EXIT_FAILURE);
    }
  else
    {
    for (int i = 0; i < array_size; i++)   // Load the array
      {
      inData >> things[i];
      }
    inData.close();
    }
  return;
  }

//******************************************************
// display_array
//******************************************************

void display_array(int things[], int array_size)
  {

  cout << "\n************************************";
  for (int i = 0; i < array_size; i++)
    {
    cout << "\nOffset: " << setw(2) << i;
    cout << " Memeber: " << setw(2) << i+1;
    cout << " value is: " << setw(3) << things[i];
    }
  cout << "\n************************************";

  return;
  }

//******************************************************
// sum_array
//******************************************************

int sum_array(int things[], int array_size)
  {
  int  total = 0;         // Accumulator

  for (int i = 0; i < array_size; i++)
    {
    total += things[i];
    }
  return total;
  }

//******************************************************
// pause
//******************************************************

void pause(void)
  {
  cout << "\n\n";
  system("PAUSE");
  cout << "\n\n";
  return;
  }

Now I have to add a function that returns an integer value after being passed an array and the number of array elements.elements. The value it should return is the average of the values that are within the array ( integer division ).
The average would be the total divided by the number of elements in the array and it will truncate to a whole number ( that's ok). Lets say it would be average_array. Just supposed to display the average within the function main following the display of the sum.

I am really having difficulties with that. I don't understand how I would do it. I hope somebody can help me

No, it wasn't.

I don't know , I just dont get it. So I just modify it so that I can get the sum?

I came up with this now..

Code:

{
average = 0;
sum = 0;
for (int i = 0; i < array_size; i++)
sum += things[i];
average = double(sum)/ array_size;
}

There's an error in there that I can't find. Would that be a good way though?