How do you define a multiline macro in C?

Question

Use '\' at line endings. – Trevor Hickey Oct 02 '16 at 20:09 — Trevor Hickey, Oct 02 '16 at 20:09

score 28 · Answer 1 · answered Oct 02 '16 at 20:13

28

End every line of definition of macro with a \

#include <stdio.h>
#define MAX(a,b) {\
    printf("%d ", a); \
    printf("%d\n", b); \
}

int main()
{
    printf("Hello, World!\n");
    MAX(4, 5);
    return 0;
}

answered Oct 02 '16 at 20:13

shriroop_

775
6
15

1

why did this receive a -1? – Luis B Oct 02 '16 at 20:16

score 5 · Answer 2 · answered Oct 02 '16 at 20:10

5

Use \ to escape line return:

#define MULTILINE_MACRO()\
    line1\
    line2

answered Oct 02 '16 at 20:10

rocambille

15,398
12
50
68

score 3 · Answer 3 · answered Oct 02 '16 at 20:12

3

Below are two C macros that are multiline

#define for_loop_begin(size)\
for (int i = 0; i < size; i++) \
{ \
for (int j = 0; j < size; j++) {


#define for_loop_end\
}\
}

answered Oct 02 '16 at 20:12

Luis B

1,684
3
15
25

why did this receive a -1? – Luis B Oct 14 '16 at 17:53

How do you define a multiline macro in C?

3 Answers3