I dont understand the syntax of 'struct' in this program.
struct structure_name
{
data_members
};
How come it doesnt have a name?
And why the data_members defined in two different curly braces?
And why devcaps [] hasnt got a type?

/
Code:
*---------------------------------------------------------
   DEVCAPS1.C -- Device Capabilities Display Program No. 1
                 (c) Charles Petzold, 1998
  ---------------------------------------------------------*/

#include <windows.h>

#define NUMLINES ((int) (sizeof devcaps / sizeof devcaps [0]))

struct
{
     int     iIndex ;
     TCHAR * szLabel ;
     TCHAR * szDesc ;
}
devcaps [] =
{
     HORZSIZE,      TEXT ("HORZSIZE"),     TEXT ("Width in millimeters:"),
} ;

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
     static TCHAR szAppName[] = TEXT ("DevCaps1") ;
     HWND         hwnd ;
     MSG          msg ;
     WNDCLASS     wndclass ;
     
     wndclass.style         = CS_HREDRAW | CS_VREDRAW ;
     wndclass.lpfnWndProc   = WndProc ;
     wndclass.cbClsExtra    = 0 ;
     wndclass.cbWndExtra    = 0 ;
     wndclass.hInstance     = hInstance ;
     wndclass.hIcon         = LoadIcon (NULL, IDI_APPLICATION) ;
     wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW) ;
     wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
     wndclass.lpszMenuName  = NULL ;
     wndclass.lpszClassName = szAppName ;
     
     if (!RegisterClass (&wndclass))
     {
          MessageBox (NULL, TEXT ("This program requires Windows NT!"),
                      szAppName, MB_ICONERROR) ;
          return 0 ;
     }
     
     hwnd = CreateWindow (szAppName, TEXT ("Device Capabilities"),
                          WS_OVERLAPPEDWINDOW,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          NULL, NULL, hInstance, NULL) ;
     
     ShowWindow (hwnd, iCmdShow) ;
     UpdateWindow (hwnd) ;
     
     while (GetMessage (&msg, NULL, 0, 0))
     {
          TranslateMessage (&msg) ;
          DispatchMessage (&msg) ;
     }
     return msg.wParam ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
     static int  cxChar, cxCaps, cyChar ;
     TCHAR       szBuffer[40] ;
     HDC         hdc ;
     int         i  ;
     PAINTSTRUCT ps ;
     TEXTMETRIC  tm ;
     
     switch (message)
     {
     case WM_CREATE:
          hdc = GetDC (hwnd) ;
          
          GetTextMetrics (hdc, &tm) ;
          cxChar = tm.tmAveCharWidth ;
          cxCaps = (tm.tmPitchAndFamily & 1 ? 3 : 2) * cxChar / 2 ;
          cyChar = tm.tmHeight + tm.tmExternalLeading ;
          
          ReleaseDC (hwnd, hdc) ;
          return 0 ;
          
     case WM_PAINT:
          hdc = BeginPaint (hwnd, &ps) ;
          
          for (i = 0 ; i < NUMLINES ; i++)
          {
               TextOut (hdc, 2, cyChar * i,
                        devcaps[i].szLabel,
                        lstrlen (devcaps[i].szLabel)) ;
               
               TextOut (hdc, 14 * cxCaps, cyChar * i,
                        devcaps[i].szDesc,
                        lstrlen (devcaps[i].szDesc)) ;
               
               SetTextAlign (hdc, TA_RIGHT | TA_TOP) ;
               TextOut (hdc, 14 * cxCaps + 35 * cxChar, cyChar * i, szBuffer,
                        wsprintf (szBuffer, TEXT ("&#37;5d"),
                             GetDeviceCaps (hdc, devcaps[i].iIndex))) ;
               
               SetTextAlign (hdc, TA_LEFT | TA_TOP) ;
               
          }
          
          EndPaint (hwnd, &ps) ;
          return 0 ;
          
     case WM_DESTROY:
          PostQuitMessage (0) ;
          return 0 ;
     }
     return DefWindowProc (hwnd, message, wParam, lParam) ;
}