C isn't that hard: void ( *( *f[] ) () ) ()

Question

I just saw a picture today and think I\'d appreciate explanations. So here is the picture:

I found this confusing and wondered if such codes are ever prac

Answer 1

I happen to be the original author of the spiral rule that I wrote oh so many years ago (when I had a lot of hair :) and was honored when it was added to the cfaq.

I wrote the spiral rule as a way to make it easier for my students and colleagues to read the C declarations "in their head"; i.e., without having to use software tools like cdecl.org, etc. It was never my intent to declare that the spiral rule be the canonical way to parse C expressions. I am though, delighted to see that the rule has helped literally thousands of C programming students and practitioners over the years!

For the record,

It has been "correctly" identified numerous times on many sites, including by Linus Torvalds (someone whom I respect immensely), that there are situations where my spiral rule "breaks down". The most common being:

char *ar[10][10];

As pointed out by others in this thread, the rule could be updated to say that when you encounter arrays, simply consume all the indexes as if written like:

char *(ar[10][10]);

Now, following the spiral rule, I would get:

"ar is a 10x10 two-dimensional array of pointers to char"

I hope the spiral rule carries on its usefulness in learning C!

P.S.:

I love the "C isn't hard" image :)