Null references redux

[Jeremie Pelletier]

Ary Borenszweig wrote:
> Walter Bright wrote:
>> Denis Koroskin wrote:
>>  > On Sat, 26 Sep 2009 22:30:58 +0400, Walter Bright
>>  > <newshound1 at digitalmars.com> wrote:
>>  >> D has borrowed ideas from many different languages. The trick is to
>>  >> take the good stuff and avoid their mistakes <g>.
>>  >
>>  > How about this one:
>>  > 
>> http://sadekdrobi.com/2008/12/22/null-references-the-billion-dollar-mistake/ 
>>
>>  >
>>  >
>>  > :)
>>
>> I think he's wrong.
> 
> Please, please, please, do some fun little project in Java or C# and 
> drop the idea of initializing variables whenever you declare them. Just 
> leave them like this:
> 
> int i;
> 
> and then later initialize them when you need them, for example different 
> values depending on some conditions. Then you'll realize how powerful is 
> having the compiler stop variables that are not initialized *in the 
> context of a function, not necessarily in the same line of their 
> declaration*. It's always a win: you get a compile time error, you don't 
> have to wait to get an error at runtime.
> 
> Until you do that, you won't understand what most people are answering 
> to you.
> 
> But I know what you'll answer. You'll say "what about pointers?", "what 
> about ref parameters?", "what about out parameters?", and then someone 
> will say to you "C# has them", etc, etc.
> 
> No point disussing non-null variables without also having the compiler 
> stop uninitialized variables.

All null values are uninitialized, but not all initializers are null, 
especially the void initializer. You can't always rely on initializers 
in your algorithms, you can always rely on null.

Kinda like all pointers are references, but not all references are 
pointers. You can't do pointer arithmetic on references.