Hi

I am new to c++ and I have a simple program that I am trying to understand .Here is the program If anyone can put some comments to what the codes mean I would be grateful.//Explain Please what these lines mean.

```
#include <iostream>
using namespace std;
int sum(int[],int);//
int main()
{
int a[]={11,33,55,77};//
int size=sizeof (a)/sizeof(int);//
cout << "sum(a,size)="<<sum(a,size)<<endl;
}
int sum(int a[],int n)//
{
int sum=0;
for (int i=0;i<n;i++)
sum+=a[i];
int Avg= sum/4;
cout<<"Avg="<<Avg<<endl;
return sum;
}
```