Passing Pointers to Functions in C++

C++ allows you to pass a pointer to a function. To do so, simply declare the function parameter as a pointer type.

Following a simple example where we pass an unsigned long pointer to a function

and change the value inside the function which reflects back in the calling function −

#include <iostream>

using namespace std;

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

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

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

// output the return 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;
}