structure in c dont understanding K&R page no. 129

[thannara123]

I am learning the c from K&R text book .and stops where the page no .129 where the following code

[COLOR=#222426][FONT=Arial] struct rect {
[/FONT][/COLOR][COLOR=#222426][FONT=Arial]struct point pt1;[/FONT][/COLOR]
[COLOR=#222426][FONT=Arial]struct point pt2;[/FONT][/COLOR]
[COLOR=#222426][FONT=Arial]};[/FONT][/COLOR]

What it does mean ?

 

[FvM]

Start reading on page 128, definition of struct point.

 

[thannara123]

Alter way of structure declaration

typedef struct point ;

struct rect {
  point pt1;
  point pt2;
};

 

[FvM]

Alter way of structure declaration

No legal typedef.

Either write

struct point{
   int x;
   int y;
};

typedef struct point tpoint;

struct rect {
  tpoint pt1;
  tpoint pt2;
};

Or

typedef struct {
   int x;
   int y;
} tpoint;

struct rect {
  tpoint pt1;
  tpoint pt2;
};

 

[bigdogguru]

I should also add you might come across the following:

typedef struct [COLOR="#FF0000"]point[/COLOR]{
   int x;
   int y;
} [COLOR="#0000FF"]tpoint[/COLOR];

Which incorporates both the struct type identifier, point, and the typedef type identifier, tpoint, into a single definition.

Or as most C compilers are case sensitive by default:

typedef struct [COLOR="#FF0000"]tpoint[/COLOR]{
   int x;
   int y;
} [COLOR="#0000FF"]TPOINT[/COLOR];

Where the struct type identifier is tpoint and the typedef type identifier is TPOINT.


BigDog