How to embed an integer in a macro string?

Question

My first time seeing stringification and token pasting. I feel like it could be a good tool for this macro:

#define MY_NUMBER   3
#define MY_STRING   "the number three: ##MY_NUMBER"
printf("%s\n", MY_STRING);

should output:

the number three: 3

Answer 1

try this

#define S_(x) #x
#define S(x) S_(x)

#define MY_NUMBER   3
#define MY_STRING   "the number three: " S(MY_NUMBER)