Re: operator precedence in c - clarifications needed

[pete]

Richard Heathfield wrote:

CBFalconer said:

>Prasad wrote:

>>I am quite familiar with C and have coded a lot. But I get stumped
on precedence rules, and I use paranthesis always. Can one of you
out there explain how the value of s is evaluated in the following
code snippet?

int a=5,s=0;
s=(++a) + (a++) + (--a) + (a--);

That's an illegal statement.

No, it isn't. Its behaviour is undefined, but it's not against the law.
Compilers aren't even obliged to diagnose it.

Neither are they obliged to compile it.

Running software that can translate and execute a C program,
is what an implementation of C is.

Whether or not running software
can translate and execute a text file
containing the line identified by CBFalconer as "illegal",
has no bearing on whether or not
that running software is a C implementation.

Code that contains that line, isn't a C program,
it's just gibberish that looks like a C program;
and if your compiler does compile it,
then you have fooled your compiler.

Followup-To:comp.lang.c

--
pete