Re: Should I explicitly initialize all member variables?

Jeff Louie <jeff_louie@xxxxxxxxx> wrote:
> Javamman.. The following two lines of code are NOT equivalent in C#.
>
> >MyClass m = null; // redundant
> MyClass m; // better?<
>
> The second line simply creates an unitialized variable. It does not
> default to null.

Yes it does - if it's a member variable. If it's a *local* variable it
remains uninitialised, but the subject line makes it clear that the
question is about member variables. From the spec, section 12.2 (ECMA
numbering):

<quote>
The following categories of variables are automatically initialized to
their default values:

* Static variables.
* Instance variables of class instances.
* Array elements.

The default value of a variable depends on the type of the variable and
is determined as follows:

* For a variable of a value-type, the default value is the same as
the value computed by the value-type's default constructor (11.1.1).
* For a variable of a reference-type, the default value is null.
</quote>

> http://www.geocities.com/Jeff_Louie/OOP/oop5.htm

There are a couple of slight errors in that, in the Java bit:

4) Value types *don't* actually derive from anything - only the
reference type which is used for boxing the value type derives
(indirectly) from Object. It's all a bit odd, but is spelled out in the
CLI spec.

9) Java has enums now too - they're very different to C# ones though
(and far superior, IMO).

--
Jon Skeet - <skeet@xxxxxxxxx>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too
.

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