1.
int[] intArr = new int[255];

2.
int[] intArr = new int[255];
rgnNumberArr.Initialize();

3.
int[] intArr = new int[255];
for( int i=0; i<intArr .lenght; i++)
{
intArr [i] = 0;
}

intArr allways initilized with 0 value?
or should I initialize it?

choose best code 1,2,3?

kiplring ha scritto:
> 1.
> int[] intArr = new int[255];
>
> 2.
> int[] intArr = new int[255];
> rgnNumberArr.Initialize();
>
> 3.
> int[] intArr = new int[255];
> for( int i=0; i<intArr .lenght; i++)
> {
> intArr [i] = 0;
> }
>
> intArr allways initilized with 0 value?
> or should I initialize it?
>
> choose best code 1,2,3?

uhm... I'm not what you can say a "good developer" :-) but I should do like
this:

int intArrayLength = 255;
int[] intArr = new int[255];
for( int i=0; i<intArr .lenght; i++)
{
intArr [i] = 0;
}


bye,
Giulio - Italia

I'm not a "good developer" either, but I'll vote for no.3.

Note that the MSDN documentation explicitly stated that "if the value type
does not have a default constructor, the Array is not modified.", so no.2 is
no better than no.1.

btw, I somehow remember I've read that the .NET framework will preinitialize
interger array to zero for you but you should never rely on this
behaviour... I'm not so sure about this...

"kiplring" <(E-Mail Removed)>
???????:(E-Mail Removed)...
> 1.
> int[] intArr = new int[255];
>
> 2.
> int[] intArr = new int[255];
> rgnNumberArr.Initialize();
>
> 3.
> int[] intArr = new int[255];
> for( int i=0; i<intArr .lenght; i++)
> {
> intArr [i] = 0;
> }
>
> intArr allways initilized with 0 value?
> or should I initialize it?
>
> choose best code 1,2,3?
>

"kiplring" <(E-Mail Removed)> wrote:

> 1.
> int[] intArr = new int[255];

All dynamic allocation with 'new' is initialized to whatever '0' means
for that type. For this array, that means the whole array will be zeroed
out.

> 2.
> int[] intArr = new int[255];
> rgnNumberArr.Initialize();

I don't know what rgnNumberArr has to do with intArr, so I can't comment
on this code.

Array.Initialize() is for value types that have constructors (i.e. from
C++); you typically don't need to call it in a C# application. Also, the
C++ folks have been toning down their guarantees on .NET about default
construction of value types, so now it's even less necessary.

> 3.
> int[] intArr = new int[255];
> for( int i=0; i<intArr .lenght; i++)
> {
> intArr [i] = 0;
> }

This loop is redundant.

-- Barry

--
http://barrkel.blogspot.com/

"kiplring" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> 1.
> int[] intArr = new int[255];
>
> 2.
> int[] intArr = new int[255];
> rgnNumberArr.Initialize();
>
> 3.
> int[] intArr = new int[255];
> for( int i=0; i<intArr .lenght; i++)
> {
> intArr [i] = 0;
> }

If you get an int[] by calling new, you'll get an array full of 0s.
If you do it from unmanaged code, you'll get whatever junk was in that
memory before.

Alun Harford

Hi,

"kiplring" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> 1.
> int[] intArr = new int[255];

The way to go !

> 2.
> int[] intArr = new int[255];
> rgnNumberArr.Initialize();

What is rgnNumberArr ?
In anyway calling Initialize is not needed, see what MSDN says about it:

This method is designed to help compilers support value-type arrays; most
users do not need this method. It must not be used on reference-type arrays.

If the Array is not a value-type Array or if the value type does not have a
default constructor, the Array is not modified.

The value-type Array can have any lower bound and any number of dimensions.

CAUTION You can use this method only on value types that have
constructors; however, value types that are native to C# do not have
constructors.

> 3.
> int[] intArr = new int[255];
> for( int i=0; i<intArr .lenght; i++)
> {
> intArr [i] = 0;
> }

Not needed, it will be done for you.



--
--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

Hi,


> int intArrayLength = 255;
> int[] intArr = new int[255];
> for( int i=0; i<intArr .lenght; i++)
> {
> intArr [i] = 0;
> }

You do not need to initialize a value type array, it will ALWAYS have a
value (contrary to what happen with a reference typed array which will be
null ), this is why a DateTime cannot be null.


--
--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

> btw, I somehow remember I've read that the .NET framework will preinitialize
> interger array to zero for you but you should never rely on this
> behaviour... I'm not so sure about this...

You CAN rely on ints being initialized to 0; .Net guarentees that this
will happen.

"kiplring" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> 1.
> int[] intArr = new int[255];
>
> 2.
> int[] intArr = new int[255];
> rgnNumberArr.Initialize();
>
> 3.
> int[] intArr = new int[255];
> for( int i=0; i<intArr .lenght; i++)
> {
> intArr [i] = 0;
> }
>
> intArr allways initilized with 0 value?
> or should I initialize it?

I think the best way to solve this problem is 1) Look up Array.Initialize()
to see what it does, and 2) Run the code to see what it produces. Much
quicker than asking people.

///ark

Lau Lei Cheong <(E-Mail Removed)> wrote:
> btw, I somehow remember I've read that the .NET framework will preinitialize
> interger array to zero for you but you should never rely on this
> behaviour... I'm not so sure about this...

Why would you "never rely on this behaviour"? Which other pieces of
behaviour which are documented in the language specification should you
not rely on?

--
Jon Skeet - <(E-Mail Removed)>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too