unsafe code and array

[Jerome]

Hi all,

I *have* to use unsafe code, but I have a questions : it seems I can't use
delete to free something like : int * myarray = new int[size].
What should I do if I wanna create/delte/resize such an array ? I'm afraid I
didn't get all about the unsafe code !
Clearly, how should I use the unsafe code to do something like that (in c++)
:
....
if(myArray != null)
delete[] myArray;
myArray = new int[newsize]
....

Thank you for your help !

Jérôme

[Richard Blewett [DevelopMentor]]

Re: unsafe code and array

"Jerome" <jlgarbage@wana doo.fr> wrote in message
news:%23aL8aaRE GHA.3528@TK2MSF TNGP12.phx.gbl. ..[color=blue]
> Hi all,
>
> I *have* to use unsafe code, but I have a questions : it seems I can't use
> delete to free something like : int * myarray = new int[size].
> What should I do if I wanna create/delte/resize such an array ? I'm afraid
> I didn't get all about the unsafe code !
> Clearly, how should I use the unsafe code to do something like that (in
> c++) :
> ...
> if(myArray != null)
> delete[] myArray;
> myArray = new int[newsize]
> ...
>
> Thank you for your help !
>
> Jérôme
>[/color]

why do you need to use unsafe code?

You don;t need to delete here because .NET is a GC'd environment and the
allocated array memory will get garbage collected once its eligible.

Regards

Richard Blewett - DevelopMentor

http://www.dotnetconsult.co.uk/weblog

http://www.dotnetconsult.co.uk

[Jerome]

Re: unsafe code and array

I agree, but maybe i missed something important : what happens if you use
the new operator 2 times on the same object ?
for instance :
int[] myArray = new int[50];
myArray = new int[25];

Can I assume it'll create a first array of 50 int, then delete it a create
an array of 25 int and GC will manage the whole memory proccess?

"Richard Blewett [DevelopMentor]" <richard at nospam dotnetconsult dot co
dot uk> a écrit dans le message de news:
OjGN%23gREGHA.3 728@tk2msftngp1 3.phx.gbl...[color=blue]
> "Jerome" <jlgarbage@wana doo.fr> wrote in message
> news:%23aL8aaRE GHA.3528@TK2MSF TNGP12.phx.gbl. ..[color=green]
>> Hi all,
>>
>> I *have* to use unsafe code, but I have a questions : it seems I can't
>> use delete to free something like : int * myarray = new int[size].
>> What should I do if I wanna create/delte/resize such an array ? I'm
>> afraid I didn't get all about the unsafe code !
>> Clearly, how should I use the unsafe code to do something like that (in
>> c++) :
>> ...
>> if(myArray != null)
>> delete[] myArray;
>> myArray = new int[newsize]
>> ...
>>
>> Thank you for your help !
>>
>> Jérôme
>>[/color]
>
> why do you need to use unsafe code?
>
> You don;t need to delete here because .NET is a GC'd environment and the
> allocated array memory will get garbage collected once its eligible.
>
> Regards
>
> Richard Blewett - DevelopMentor
> http://www.dotnetconsult.co.uk/weblog
> http://www.dotnetconsult.co.uk
>[/color]

[Joanna Carter [TeamB]]

Re: unsafe code and array

"Jerome" <jlgarbage@wana doo.fr> a écrit dans le message de news:
ecrLXoREGHA.102 8@TK2MSFTNGP11. phx.gbl...

|I agree, but maybe i missed something important : what happens if you use
| the new operator 2 times on the same object ?
| for instance :
| int[] myArray = new int[50];
| myArray = new int[25];
|
| Can I assume it'll create a first array of 50 int, then delete it a create
| an array of 25 int and GC will manage the whole memory proccess?

Yes, otherwise the Array.Resize method couldn't work.

Joanna

--
Joanna Carter [TeamB]
Consultant Software Engineer

[Richard Blewett [DevelopMentor]]

Re: unsafe code and array

"Jerome" <jlgarbage@wana doo.fr> wrote in message
news:ecrLXoREGH A.1028@TK2MSFTN GP11.phx.gbl...[color=blue]
>I agree, but maybe i missed something important : what happens if you use
>the new operator 2 times on the same object ?
> for instance :
> int[] myArray = new int[50];
> myArray = new int[25];
>
> Can I assume it'll create a first array of 50 int, then delete it a create
> an array of 25 int and GC will manage the whole memory proccess?
>[/color]

You can't use the new operator on the same *object* the new operator creates
a new object. What you are referring to is assigning the new object to the
same *reference*. And what happens in that case?

Well assuming that the no other references exist to the old array then next
time the GC runs it will collect it (this is a simplification of the process
but in principle this is what happens).

Regards

Richard Blewett - DevelopMentor

http://www.dotnetconsult.co.uk/weblog

http://www.dotnetconsult.co.uk