C Standard Library - <stddef.h>
Introduction
stddef .h The header file defines various variable types and macros. Most of these definitions also appear in other header files.
Library variables
The following are the variable types defined in the header file stddef.h:
| Serial number | Variables & Description |
|---|---|
| 1 | ptrdiff_t This is a signed integer type that is the result of subtracting two pointers. |
| 2 | size_t This is the unsigned integer type that is the result of the sizeof keyword. |
| 3 | wchar_t This is a wide character constant-sized integer type. |
Library macros
The following are the macros defined in the header file stddef.h:
| Serial number | Macro & Description |
|---|---|
| 1 | NULL This macro is the value of a null pointer constant. |
| 2 | offsetof(type, member-designator) This will generate an integer constant of type size_t, which is a structure member relative to the structure The byte offset from the beginning. Members are given in member-designator and the name of the structure is given in type. |
