#include preprocessing directive has been used throughout this text. The
#include directive causes a copy of a specified file to be included in place of the directive. The two forms of the
#include directive are
#include <filename> #include "filename"
The difference between these is the location the preprocessor searches for the file to be included. If the filename is enclosed in angle brackets (
>)—used for standard library header files—the preprocessor searches for the specified file in an implementation-dependent manner, normally through predesignated directories. If the file name is enclosed in quotes, the preprocessor searches first in the same directory as the file being compiled, then in ...