Question

In C, What is the #line used for?

Answer 1

In C, #line is used as a preprocessor to re-set the line number in the code, which takes a parameter as line number. Here is an example for the same.

#include <stdio.h>								/*line 1*/
												/*line 2*/
	int main(){									/*line 3*/
												/*line 4*/
	printf("Hello world\n");					/*line 5*/
	//print current line						/*line 6*/
	printf("Line: %d\n",__LINE__);				/*line 7*/
	//reset the line number by 36				/*line 8*/
	#line 36	/*reseting*/
	//print current line						/*line 36*/
	printf("Line: %d\n",__LINE__);				/*line 37*/
	printf("Bye bye!!!\n");						/*line 39*/
												/*line 40*/
	return 0;									/*line 41*/
}												/*line 42*/