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c++cmingw32

Does "complicated-nested" "for/if statement" really follow the C standards?

I've known that

for (...; ...; ...)
    printf ("Fulfill the limits.");

and

if  (...)
    printf ("Fulfill the limits.");

are C standard.

But

for (...; ...; ...)
    if (...)
       for (...; ...; ...)
           if (...)
              for (...; ...; ...)
                  printf ("Fulfill all the limits.");

is compiled successfully, and run without (logic) errors.

Does complicated-nested for/if statement really follow the C standards or just mingw32 compiler-specific?

Any reference?

Thanks.

Solution

  • It is perfectly valid syntax. The syntax is not complicated, simply nested like x1 + (x2 + (x3 + ..).

    That is, if/for is a statement and if/for contains a statement. This can be seen in the recursive BNF grammar rules:

    statement:
   "if" "(" expression ")" statement |
   "for" "(" expression? ";" expression? ";" expression? ")" statement |
   ..