Размер динамического массива

#include <iostream>
#include <conio.h>
#include <clocale>
#include <ctime>
 
using namespace std;
 
void CreateRandomArray(int*&, int, int, int);
void PrintArray(int*);
 
int main()
{
    int* arr = NULL;
    
    int s = 5;
    int b = 6;
    int e = 10;
 
    CreateRandomArray(arr, s, b, e);
    PrintArray(arr);
 
    _getch();
    return 0;
}
 
 
void CreateRandomArray(int*& _array, int _size, int _begin, int _end)
{
    _array = NULL;
    _array = new int[_size];
 
    for (int i = 0; i < _size; i++)
        *(_array + i) = _begin + rand() % (_end - _begin + 1);
}
 
 
void PrintArray(int* _array)
{
    int size = sizeof _array / sizeof *_array;
    cout << "Array:" << endl;
    cout << "\t";
    for (int i = 0; i < size; i++)
        cout << *(_array + i) << " ";
}

int size = sizeof _array / sizeof *_array;

#include <iostream>
#include <windows.h>
#include <malloc.h>
using namespace std;
int main() {
    srand(time(NULL));
    PBYTE originalBytes = NULL;
    originalBytes = new BYTE[rand()%3];
    size_t originalBytesSize = (originalBytes == NULL) ? 0U : _msize(originalBytes) / sizeof(*originalBytes);
    cout << originalBytesSize << endl;
}

#define MAKE16(high, low) (WORD)(low & 0xff | ((high & 0xff) << 8))
#define LOBYTE(low)  (BYTE)(low & 0xff)
#define HIBYTE(high) (BYTE)((high >> 8) & 0xff)
 
Create() 
{ 
   File = new char[hParam]; 
   File[0] = HIBYTE(hParam); 
   File[1] = LOBYTE(hParam);
}

short Len = MAKE16(File[0], File[1]);