ExplanationIn the above program #i f ndef checks for the identifier T. If it is defined the #else block
is executed. On execution of the block the output of the program is "Macro is defined". In case the
identifier is undefined the #else block is executed and output is " Macro is not defined."
11.8 THE *error DIRECTIVE
The # error is used to display user defined message during compilation of the program. The
syntax is a’s given below.
# if1defined (identifier)
# error<ERROR MESSAGE>
#endif
11.13 Write a program to display user-defined error message using #error dire
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month, and much more.
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
Julian F.
Head of Cybersecurity
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.
Addison B.
Field Engineer
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.
Amir M.
Data Platform Tech Lead
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.