CArray - GetUpperBound

CArray::GetUpperBound() is used to get the UpperBound of the array(last index of the array).
Because array indexes are zero-based, this function returns a value 1 less than GetSize.
GetUpperBound( ) give –1 when array contains no elements.

CArray<cpoint,cpoint> myArray;
CPoint pt;
for (int i = 0; i < 10; i++)
   myArray.Add(CPoint(i, 2 * i));
for (int i = 0; i <= myArray.GetUpperBound(); i++)
{
   pt = myArray.GetAt(i);
   pt.x = 0;
   myArray.SetAt(i, pt);
}

CArray::GetSize() return the size off array.Because indexes are zero-based, the size is 1 greater than the largest index. Calling this method will generate the same result as the CArray::GetCount method.

CArray<cpoint,cpoint> myArray;
for (int i = 0; i < 10; i++)
   myArray.Add(CPoint(i, 2*i));
for (int i = 0; i < myArray.GetSize(); i++)
{
   CPoint& pt = myArray.ElementAt(i);
   pt.x = 0;
}

You can call size() function for Vectors.

#include <iostream>
#include <vector>
int main ()
{
  std::vector<int> myints;
  std::cout << "0. size: " << myints.size() << '\n';
  for (int i=0; i<10; i++) myints.push_back(i);
  std::cout << "1. size: " << myints.size() << '\n';
  myints.insert (myints.end(),10,100);
  std::cout << "2. size: " << myints.size() << '\n';
  myints.pop_back();
  std::cout << "3. size: " << myints.size() << '\n';
  return 0;
}