CArray is a collection template which can store all data types. Unlike a normal C++ Array this MFC Collection template can grow and shrink depending on the needs. This allows memory to be utilized efficiently in MFC programs. This template is declared in afxtempl.h. This class can be used wherever there is a need to store a list of similar typed objects.
This article describes how to add to, access from and remove objects from the MFC Collection template CArray.
CArray – Adding an element:
The member function Add can be used to add objects to the Array. Before using CArray template, CArray has to be declared to accept the corresponding type of object. This code sample declares and uses CString.
#include <Afxwin.h>
#include <Afxtempl.h>
void main()
{
CString l_strValue;
CArray<CString,CString> l_CArray;
for(int i=0;i< 20; i++)
{
//Use the CString format function to create different values
l_strValue.Format("Value %d",i);
//Add the formatted CString to CArray
l_CArray.Add(l_strValue);
}
}
CArray – Accessing the elements:
The member function GetAt can be used to access the data stored in CArray. This returns the object on the type stored. Modifying the value at a given node is carried out by using SetAt function.
#include <Afxwin.h>
#include <Afxtempl.h>
void main()
{
CString l_strValue;
CArray<CString,CString> l_CArray;
for(int i=0;i< 20; i++)
{
//Use the CString format function to create different values
l_strValue.Format("Value %d",i);
//Add the formatted CString to CArray
l_CArray.Add(l_strValue);
}
//This part takes care of accessing and printing the data from CArray
CString l_strGetVal;
for(i=0;i<=l_CArray.GetUpperBound();i++)
{
l_strGetVal = l_CArray.GetAt(i);
printf("%sn",l_strGetVal);
}
}
CArray – Removing the elements:
There are two different functions to remove the data from CArray. RemoveAll function can be used to remove all the elements. The RemoveAt function can be used to remove an element from a specific location.
l_CArray.RemoveAll() //This will remove all the elements from CArray l_CArray.RemoveAt(10); //This will remove the 10th element from CArray
CString was used in the above example with CArray. But all complex data types can be stored in this MFC Collection template.