What's the use of do while(0) when we define a macro?

Sample code:

 

#include <stdio.h>

#define INIT do { \
	printf("line1\n"); \
} while (0)

#define INIT_ { \
	printf("line1\n"); \
}

void correct() {
	if (1) 
		INIT;
	else
		printf("here is the else\n");
}

void wrong() {
 if (1) 
	 INIT_; // compile error
 else
	 printf("here is the else\n");
}

int main(int argc, const char *argv[]) {
	if (1) 
	{ printf("then\n"); }; // compile error
	else
		printf("else\n");
}

 

Refer to http://stackoverflow.com/questions/923822/whats-the-use-of-do-while0-when-we-define-a-macro