null [re: spec#]

[Nick Sabalausky]

"Nick Sabalausky" <a at a.a> wrote in message 
news:ibc4h2$1mmn$1 at digitalmars.com...
> "Daniel Gibson" <metalcaedes at gmail.com> wrote in message 
> news:ibbp25$ls8$1 at digitalmars.com...
>> Nick Sabalausky schrieb:
>>> "so" <so at so.do> wrote in message news:op.vlv3iukp7dtt59 at so-pc...
>>>>> There's no usage of an undeclared variable, but the right-hand-side of 
>>>>> the
>>>>> second line uses 'i' before *the programmer* initializes it. Yes, the 
>>>>> D
>>>>> compiler chooses to automatically initialize it, but by doing so it 
>>>>> silently
>>>>> creates a bug every time the programmer intends 'i' to start out as 
>>>>> anything
>>>>> other than 0. And it's not easily noticed since 0 is a commonly-used 
>>>>> value.
>>>>> (Something like 0xDEADBEEF would at least be an improvement (albeit a 
>>>>> small
>>>>> one) since at least that would stand out more and likely fail more
>>>>> spectacularly.)
>>>> So you want language force you to type either "int x=0;" or "int 
>>>> x=void;".
>>>> Fair enough and i agree it "might" be a bit better. But you are making 
>>>> it as it is something so much important.
>>>
>>> I tend to get a bit fired up by it because Walter's reasoning on it 
>>> being *better* to automatically assume some init value baffles me.
>>>
>>
>> It gives deterministic results/errors.
>> For example, when your code works when an int is initialized with 0 (but 
>> you didn't initialize it), it may work most of the time in C and fail 
>> randomly. In D it will always work. Same thing the other way round.
>> Or if you do some calculation with an uninitialized int value.. I guess 0 
>> is one of the easiest values to spot: on multiplication it creates 0 and 
>> on addition it doesn't change to value so by looking at the unwanted 
>> result of a calculation you probably can see the error more easily than 
>> on some other value (or even a random value, that may create results that 
>> look about right).
>
> Where are people getting the idea that I've said C's behavior is better 
> than D's? Once again, I'm not talking about D vs C (ie "int i;" leaves 'i' 
> in an undefined state), I'm talking about D vs C# (ie, "int i;" causes 
> compile-time errors when 'i' is read before being written to).
>

Again, saying "Not giving compile-time errors on reading before writing is 
good because C leaves values in an undefined state" **makes no sense**. It's 
a complete non-sequitor.