Predefined Macros

Introduction#

ANSI C defines a number of macros. Although each one is available for your use in programming, the predefined macros should not be directly modified.

Syntax#

1. DATE The current date as a character literal in “MMM DD YYYY” format
2. TIME The current time as a character literal in “HH:MM:SS” format
3. FILE This contains the current filename as a string literal.
4. LINE This contains the current line number as a decimal constant.
5. STDC Defined as 1 when the compiler complies with the ANSI standard.

Predefined Macros

#import <Foundation/Foundation.h>

int main()
{
   NSLog(@"File :%s\n", __FILE__ );
   NSLog(@"Date :%s\n", __DATE__ );
   NSLog(@"Time :%s\n", __TIME__ );
   NSLog(@"Line :%d\n", __LINE__ );
   NSLog(@"ANSI :%d\n", __STDC__ );
   
   return 0;
}

When the above code in a file main.m is compiled and executed, it produces the following result:

2013-09-14 04:46:14.859 demo[20683] File :main.m
2013-09-14 04:46:14.859 demo[20683] Date :Sep 14 2013
2013-09-14 04:46:14.859 demo[20683] Time :04:46:14
2013-09-14 04:46:14.859 demo[20683] Line :8
2013-09-14 04:46:14.859 demo[20683] ANSI :1