向函数传递二维数组

要理解计算数组的平均值，我们需要在下面声明一个函数。逐行循环读取

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;
}

之后，将该值调用给main函数。

#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;
}

我的问题是，如果我想计算row*col的平均值呢?我要申报这样的东西吗?设row和col的大小为arr[3][6]

double getAverage(int arr[][6], int noOfrows, int noOfcol)
{
    float sum=0, average;
    for (int i = 0 ; i < noOfrows ; i++) {
        for (int j = 0; j<noOfcol; j++) {    
        sum = sum + arr[i][j];    
        }
    }
        average = (float)sum / (float)(noOfcol*noOfrows);
        cout << "   " << average;
        return average; 
}

这是我的代码

int main()
{   
    int sales[3][6] = {{1000, 800, 780, 450, 600, 1200},
                       {800, 900, 500, 760, 890, 1000},
                        {450, 560, 570, 890, 600, 1100}};
    int avg;
    int choice;//menu choice
    const int computeAverage_choice = 1,
              computeTotal_choice = 2,
              listMaxMin_choice = 3,
              Exit_choice = 4;
    do
    {   
            //displayMenu(); // Show Welcome screen
            choice = displayMenu();
            while (choice < 1 || choice > 4)
         {
               cout << "Please enter a valid menu choice: " ;
               cin >> choice;
         }
            //If user does not want to quit, proceed.
         if (choice != Exit_choice)
         {  
                    switch (choice)
                    {
                           case computeAverage_choice:
                                avg = computeAverage(sales, 3, 6);
                                cout<<"The averge:" << avg;
                                break;
                           case computeTotal_choice:
                                //reserves
                                break;
                           case listMaxMin_choice:
                                //reserves
                                break;
                    }
         }
         } while (choice != Exit_choice);
            return 0;
}