C++ Turning arrays into functions? - c++

Question

I have been attempting this for hours to no avail, as you can see in my code I have separate functions, they were all together in main, but I am required to turn each into a separate function. However when I try anything I get errors, even when I try to pass parameters. Can someone point me in the right direction?
#include <iostream>
#include <cstdlib>
#include <ctime>
void printarray();
void average();
void largestnumber();
using namespace std;
int main()
{
printarray();
average();
largestnumber();
}
void printarray() {
srand(time(0));
int n[10], tot = 0;
for (int i = 0; i < 10; i++)
{
n[i] = (1 + rand() % 100);
cout << n[i] << endl;
}
}
void average() {
int j, tot = 0, n[10];
for (j = 0; j < 10; j++)
{
tot += n[j];
}
cout << "The average of the numbers in the array are " << tot / j << endl;
}
void largestnumber() {
int w = 1, int n[10];
int temp = n[0];
while (w < 10)
{
if (temp < n[w])
temp = n[w];
w++;
}
cout << "The largest number in the array is " << temp << endl;
}

Answer 1

The array you are working with needs to be passed in to each function, so the same array is used everywhere. It is a good idea to pass the size as well, just for flexibility reasons.
Now your functions pretty much work as you wrote them.
#include <iostream>
#include <cstdlib>
#include <ctime>
void printarray(int n[], size_t size);
void average(int n[], size_t size);
void largestnumber(int n[], size_t size);
using namespace std;
int main()
{
const size_t arr_size = 10;
int n[arr_size];
printarray(n, arr_size);
average(n, arr_size);
largestnumber(n, arr_size);
}
void printarray(int n[], size_t size) {
srand((unsigned int)time(0));
int tot = 0;
for (size_t i = 0; i < size; i++)
{
n[i] = (1 + rand() % 100);
cout << n[i] << endl;
}
}
void average(int n[], size_t size) {
size_t j;
int tot = 0;
for (j = 0; j < size; j++)
{
tot += n[j];
}
cout << "The average of the numbers in the array are " << tot / j << endl;
}
void largestnumber(int n[], size_t size) {
size_t w = 1;
int temp = n[0];
while (w < size)
{
if (temp < n[w])
temp = n[w];
w++;
}
cout << "The largest number in the array is " << temp << endl;
}
One simple improvement is to break the printarray out into an initarray function that fills the array and printarray that prints the content.
It would also be a good idea to do some checking for things like an empty array (functions assume n[0] exists, for instance).
The next obvious step is to put all this in a class. Also, if you are allowed to, the c array should be replaced with a vector, as that does a great job of keeping all the resource information together.