'Cannot convert 'float' to 'float*' for argument '1' - c++

Question

I'm an ICT student, studying C++, and I find it very interesting. However, while experimenting, I came up to something I can't fix myself nor find on the net.
This is the code:
#include <iostream>
using namespace std;
float average(float array[10], float &average){
int i = 0;
for( i = 0; i != 10; i++ ){
cout << "Vett ("<<i<<") = ";
cin >> array[i];
while(cin.fail())
{
cin.clear();
cin.ignore();
system("Color 5C");
cout << "\nPlease insert a number: ";
cin >> array[i];
}
average = average + array[i];
}
average = average / 10;
return array[10];
return average;
}
main(void){
float vett[10], media;
int i;
char loop;
vett[10] = 0;
media = 0;
do{
system("cls");
system("Color 00");
cout<<"****************************************"<<endl;
cout<<"*** INSER THE DATA TO COMPUTE ***"<<endl;
cout<<"****************************************\n"<<endl;
/* for( i = 0; i != 10; i++ ){
cout << "Vett ("<<i<<") = ";
cin >> vett[i];
while(cin.fail())
{
cin.clear();
cin.ignore();
system("Color 5C");
cout << "\nPlease insert a number: ";
cin >> vett[i];
}
media = media + vett[i];
}
media = media / 10;
*/
average(vett[10],media);
for( i = 0; i != 10; i++ ){
cout << vett[i]<<" ";
}
if(media == 0){
cout << "\nATTENTION the average equals to = "<<media<<endl;
}
else{
cout << "\nThe average is"<<media<<endl;
}
printf("\n");
cout << "\nDo You want to continue? Y/N";
cin >> loop;
}
while(loop == 'Y' || loop == 'y');
system("pause");
}
For some reason I couldn't set in the 'average' function the array as a pointer (&array), perhaps because the array is already a pointer. Nonetheless, removing it gives me the following error:
"Cannot convert 'float' to 'float*' for argument '1' to 'float average(float*,float&)'
If I call the function this way
average(&vett[10],media);
it works, but returns weird values in the array.
As you can see, I commented the same thing I put in the function, which works perfectly, unless..I put it in a function. I assume I've done something wrong with the function call, can anybody help me understand?

Answer 1

First of all, note that main(void){ is not a valid signature for main.
It should be:
int main(void){
Then:
float vett[10];
vett[10] = 0;
This is not valid. Array indices start at 0, so index 10 is out of bounds, as it would require an array with size 11.
Also, as your average function takes as first argument a float array, you'll need to pass it this way:
average(vett,media);
Using:
average(&vett[10],media);
Will pass a pointer to the data located right after the array, so obviously you'll get junk values.

Answer 2

Don't use func(void) in C++, it's some sort of deprecated. Use func() instead.
If you have float vett[10];, then vett[10] is invalid. You must use only vett[0 .. 9]
float average(float array[10], float &average) actually means float average(float *array, float &average). (Second form is more common way to declare pointer arguments.) If you want to call it with vett as argument, just use average(vett, media);Names of an arrays, when used as pointers, are automatically converted to pointer to first element of an array. So hereaverage(vett, media);vett means &vett[0].

Answer 3

The number in the square brackets has two meanings:
In a declaration like float vett[10]; it is the size of the array
When not in a declaration, like average(&vett[10],media); it means the eleventh element of the array.
average(&vett[10],media); is passing the address of the eleventh element to the function. The function interprets it as the beginning of the array, which is wrong and causes undefined behaviour when the elements outside of the array are accessed.
Because you want to pass the whole array, you should use
average(vett,media);

Answer 4

I'll add a little more to the help...
Your average method has two return statements at the end of it. The final one (the one you will be wanting) will never be reached, because the method will return on the first one...

Answer 5

In the function instead of this
float average(float array[10], float &average){
you have to put this :
float average(float *array, float &average){