Re: MSIE integer overflows

[xenophi1e <oliver.lavery () sympatico ca>]

In-Reply-To: <004e01c319fb$7ec41050$0100a8c0@grotedoos>


> Not true: "++i" will increase i first and return the result of that
> increased i where "i++" will return i and then increase it:
> -- example.js --
> var i=1;
> document.write(++i); // prints 2, i=2;
> document.write(i++); // prints 2, i=3;
> -- cut here --

Yes, of course.

Again, I'm talking about C here, simply because I don't know JS to this 
level of detail. But...

document.write((i==++i) + ' ' + (i==++i) + '<BR>');

Seems like ambiguous code that might rely on unspecified behaviours. 
Postincrement and preincrement are gotchas in C. For example the 
following code:

i = 2;
printf ("%d", i++ * i++);

Often does not print 6 as you might think, but rather prints 4. The 
reason is that the postincrement operator increments the values before 
the next sequence point, not necessarily the next _operation_.

I was just pointing out that using expressions like i == ++i seems a bit 
suspect. I'm not certain, but I believe a C compiler is free to do both 
increments prior to the rest of the expression. It does seem like it 
should always be a tautology, though. 

Do you get the same results if you write the same code less ambiguously?

Cheers,
~ol