char[] initialization

[Robert Atkinson]

Hasan Aljudy wrote:
> 
> 
> Derek wrote:
>> On Sat, 29 Jul 2006 06:29:21 -0600, Hasan Aljudy wrote:
>>
>>
>>> kris wrote:
>>>
>>>> Andrew Fedoniouk wrote:
>>>>
>>>>
>>>>> Could somebody shed light on the subject:
>>>>>
>>>>> According to http://digitalmars.com/d/type.html
>>>>>
>>>>> characters in D are getting initialized by following values
>>>>>
>>>>> char -> 0xFF
>>>>> wchar -> 0xFFFF
>>>>> dchar -> 0x0000FFFF
>>>>>
>>>>> what is the idea to have string initialized by valid character code 
>>>>> instead of 0?
>>>>
>>>> Try google?
>>>>
>>>> http://www.digitalmars.com/d/archives/digitalmars/D/3239.html
>>>
>>> I don't understand why the compiler should initialize variables to 
>>> illegal values!!
>>>
>>> OK, is it because you have to initialize variables explicitly?
>>> Just WHY?
>>>
>>> As far as I know, the notion that non-initialized variables are bad 
>>> is a side-effect of the C (and C++) language, because non-inited 
>>> variables are garbage.
>>>
>>> However, in D (and Java .. and others), vars are always initialized.
>>> So, if the compiler can init variables to good defaults, why should 
>>> it still be considered a bad habit not to init variables explicitly? 
>>> That just makes no sense to me.
>>
>>
>> I believe that D's philopsophy is that all datatypes are initialized to
>> 'invalid' values if they possibly can be. The ones that can't are 
>> integers,
>> bytes, and bools. References, floating point values, and characters are
>> initialized to 'wrong' values.
>>
> 
> I know .. I was asking "but why?" :(

The intent I believe is to signal the programmer as soon as possible 
showing they have missed something.  In C/C++ an un-initialised variable 
can easily survive thousands of debug runs until it 'initialises' to a 
completely wrong value.  Most often on a release build and a end-users 
system.

Take floats.  By starting at NaN, from the very start you'll know you 
missed initialising it.  You'll catch the error earlier in your debug 
process.