What does #x inside a C macro mean?

Question

For example I have a macro:

#define PRINT(int) printf(#int \"%d\\n\",int)

I kinda know what is the result. But how come #int repersent the

Answer 1

That is a bad choice of name for the macro parameter, but harmless (thanks dreamlax).

Basically if i write like so

PRINT(5);

It will be replaced as

printf("5" "%d\n",5);

or

printf("5 %d\n",5);

It is a process called Stringification, #int is replaced with a string consisting of its content, 5 -> "5"