Calculate average number from char array - c++

Question

Im trying to calculate the average out of a couple of number inside an char array. The reason for this is that i imported data from a text document and i made it read only every 2nd line to get the numbers that i wanted.
Now i need to get the average out of these numbers but i cant make it work. I'm starting to get mad about this and i feel that the solution would be rather simple.
EDIT:
The file consists of names and numbers. I.e:
Jason Smith
32
Mary Jane
52
Stevie Wonder
68
Micheal Jackson
59
#include <fstream>
#include <iostream>
using namespace std;
double averageNum(char array[], int size) { // A function to calculate the average number
int sum = 0;
double avg;
for(int i=0; i<size; i++){
array[i]+= sum;
}
avg = sum / size;
return avg;
}
int main(){
char age [50][30];
double avg;
int rows = 0;
ifstream elevInfo("elevinfo.txt"); // Opens a stream to get data from the document
if (! elevInfo){ // Error message if the file couldn't be found
cout << "Could not find the file elevinfo.txt" << endl;
return (1);
}
while(elevInfo.getline(age[rows/2], 30)){ // Reading every 2nd line to an array
rows++;
}
avg = averageNum(age[], rows); // Function call with the numbers from the array and the variable rows as a pointer
cout << "Average age equals: " << avg << endl;
}

Answer 1

this is one of many possible solutions for your problem:
int main()
{
// Opens a stream to get data from the document
ifstream elevInfo("elevinfo.txt");
// Error message if the file couldn't be found
if (!elevInfo)
{
cout << "Could not find the file elevinfo.txt" << endl;
return (1);
}
int sum = 0;
int lineCounter = 0;
// loop till end of file
while (!elevInfo.eof())
{
// prepare buffer
char line[30];
// read line into buffer
elevInfo.getline(line, 30);
// do this every second line
if (lineCounter % 2 == 1)
{
// get age as int using function atoi()
int age = atoi(line);
// increase sum by the current age
sum += age;
}
// increment line-counter
lineCounter++;
}
// calculate the average
// divide lineCounter by 2 because only every second line in your file contains an age
double avg = sum / (lineCounter / 2.0);
cout << "Average age equals: " << avg << endl;
return 0;
}
As you can see it also doesn't need the function averageNum.