C++函数接受指针参数

#include <iostream>

using namespace std;

// function declaration:
double getAverage(int *arr, int size);

int main () {
   // an int array with 5 elements.
   int balance[5] = {1000, 2, 3, 17, 50};
   double avg;

   // pass pointer to the array as an argument.
   avg = getAverage( balance, 5 ) ;

   // output the returned value 
   cout << "Average value is: " << avg << endl; 

   return 0;
}

double getAverage(int *arr, int size) {
   int i, sum = 0;       
   double avg;          

   for (i = 0; i < size; ++i) {
      sum += arr[i];
   }
   avg = double(sum) / size;

   return avg;
}