C Language Macro Definition

1#include <stdio.h>2#include <unistd.h>3 4 /*#是 "string" means that the # that appears in the macro definition is to convert the following arguments into a string*/5 #defineLog_error (Err) fprintf (stderr, #err)6 7 /*"# #" is a way of separating connections, which are separated first and then forced to connect.*/8 #defineTest (type, name) type type# #_ # #name9 #defineTest2 (type, name) type type_# #type # #_name_ # #nameTen  One voidMainvoid) A { -Testint, num); -Test2 (int, num); theLog_error (1234); -}

The code snippet above TEST.C after macro expansion is as follows:

/**/void main (void) {    int  int_num;     int type_int_name_num;     " 1234 " );}

C Language Macro Definition