Why doesn't a+++++b work?

Question

int main ()
{
   int a = 5,b = 2;
   printf(\"%d\",a+++++b);
   return 0;
}

This code gives the following error:

error: lval

Answer 1

Your compiler desperately tries to parse a+++++b, and interprets it as (a++)++ +b. Now, the result of the post-increment (a++) is not an lvalue, i.e. it can't be post-incremented again.

Please don't ever write such code in production quality programs. Think about the poor fellow coming after you who needs to interpret your code.