How to improve?

[knatte1]

Hello there! I just start with C++ about 1 week ago. Anyway my teacher told me to use array instead of writing all the "num1, num2, num3.....". He told me to use this header:

float medel(int v[], int n)

I did not understand that, but i did come up with this code:

n = numbers
medel = average

#include <iostream>

using namespace std;

int main()
{
    int n[10];
    float medel = 0;

    cout << ""Welcome to the program. Enter 10 positive numbers: ";

    for(int i = 0;i < 10;i++){
        cin >> n[i];
        medel +=((float)n[i]/10);
    }
    cout << "The average of ten numbers entered is: " << medel << endl;
    return 0;
} 

What did the teacher mean? What can be improved with the code I done?

Thanks!

[tipaye]

I think you've done what the teacher meant, mostly :-)
In line 7 you've created an array of 10 integers, which means you now have 10 integers that you can manage as group, using a single label (n).

The elements of your array, i.e. your 10 integers are n[0], n[1],...[n[8], n[9]

In line 13 you are getting input of 10 integers from the user and storing them in these elements one at a time, and computing the average as you go along - actually, since you're computing the average on the fly, you don't need that array at all.

I think what the teacher really meant was for you to do this as a function, like this:

#include <iostream>

using namespace std;

float medel(int v[], int n)
{
	float res = 0.0;
    for(int i = 0;i < n;i++){
        cin >> v[i];
        res +=((float)v[i]/n);
    }
	
	return res;
}

int main()
{
	const int num = 10;
    int n[num] = {0};

    cout << "Welcome to the program. Enter 10 positive numbers: ";
    cout << "The average of ten numbers entered is: " << medel(n, num) << endl;
    return 0;
} 

Consider using a vector instead of array
Consider using double instead of float
Consider using more descriptive variable names
Consider not using magic numbers like "10", prefer a symbolic name instead

Of course there are better ways of doing this, but I appreciate you're learning from a teacher and you have to get a good grade, which sometimes means doing things the teacher's way or else.

http://www.cplusplus.com/doc/tutorial/arrays/
http://www.cplusplus.com/doc/tutorial/functions/


Perhaps a little better:

#include <iostream>
#include <vector>

using namespace std;

double medel(const vector<int> &numbers)
{
	double res = 0.0;
	for (int num : numbers)
		res += (double) num / numbers.size();
	return res;
}

int main()
{
    cout << "Welcome to the program. Enter 10 positive numbers: ";
	constexpr int nums = 10;
	vector<int> numbers;
    for(int i = 0;i < nums;i++){
		int x;
        cin >> x;
		numbers.push_back(x);
    }
	
    cout << "The average of ten numbers entered is: " << medel(numbers) << endl;
    return 0;
} 

[knatte1]

Thanks for this answer! :)