How to pass arguments from window to the windowProc function

How to pass arguments from window to the windowProc function :


CREATESTRUCT str;
int*i = new int();
*i = 40;
str->lpCreateParams = i;


WindowProc()
{
switch(Msg)
{

int* j = (int*) ((LPCREATESTRUCT(lParam)) ->lpCreateParams)

}
}


Another one way is we can also attach the Window parameter at the time of
WNDcLASS registration.

wc.cbWndExtra = i;

we can get this value using GetWindowLong()

int* j = (int*) GetWindowLong(hWnd,GWL_USERDATA);



SetWindowLong() fn is also available

we can also use GetWindowLongPtr() or SetWindowLongPtr() for this purpose.