Issue using functions (c++) - c++

Question

so I am having a little bit of trouble getting this program to work without it throwing the errors:
"request for member 'insertArray' in 'arr', which is of non-class type 'int [10]' " and
"request for member 'print' in 'arr', which is of non-class type 'int [10]' ".
Both of those errors have to do with using my functions with an array, you can see the code below:
#include <iostream>
using namespace std;
int size = 0;
int *arr;
void insertArray(int val)
{
int i = 0;
while (i < size && arr[i] < val)
i++;
for (int k = size - 1; k >= i; k--)
{
arr[k + 1] = arr[k];
}
arr[i] = val;
size++;
}
void print()
{
cout << "The array is: ";
for (int j = 0; j < size; j++)
{
cout << arr[j];
}
}
int main()
{
int arr[10];
cout << "Please enter 5 values: \n";
for (int i = 0; i < 5; i++)
{
int num = 0;
cin >> num;
arr.insertArray(num); // Error 1: vs code error squiggles say: "expression must have class type"
arr.print(); // Error 2: vs code error squiggles say: "expression must have class type"
}
return 0;
}
I don't know how to fix the errors or what they mean either.
Thanks for the help in advance folks!

Answer 1

arr is just a plain-old C array, you can't define new functions on it. You need to define a class or struct if you want to do that.
What you have here is procedural code, so you're constrained by that model and must pass in arr as an argument.
I've tried to wrangle your original code into this form with as few modifications as necessary:
#include <iostream>
void printArr(const int* arr, const size_t size)
{
std::cout << "The array is: ";
for (int j = 0; j < size; j++) {
std::cout << arr[j];
}
std::cout << std::endl;
}
int main()
{
const size_t count = 5;
int arr[count];
std::cout << "Please enter 5 values: \n";
for (int i = 0; i < 5; i++)
{
std::cin >> arr[i];
}
printArr(arr, count);
return 0;
}
The whole insertArray function was just too confusing so I deleted it presuming what you were trying to do was add things at the end of the array anyway.