Dynamic array

[Cleber Schönhofen]

Hi,
I need a dynamic array of objects, but don´t work.

its work :
DadosDoTime[] tt = new DadosDoTime[100];
int i = 0;
while (rd.Read())
{
tt[i] = new DadosDoTime();
tt[i].pos = 0;
tt[i].classificacao = 0;
i++;
}

its don´t work :

DadosDoTime[] tt;
int i = 0;
while (rd.Read())
{
tt[i] = new DadosDoTime();
tt[i].pos = 0;
tt[i].classificacao = 0;
i++;
}

why ?

--
Cleber Schönhofen
Infobola

[Jon Skeet [C# MVP]]

Re: Dynamic array

On Sep 26, 1:40 pm, "Cleber Schönhofen" <cleber...@hotm ail.comwrote:

    I need a dynamic array of objects, but don´t work.

Arrays are always fixed in size in .NET.

Sounds like you want a List<DadosDoTim einstead:

List<DadosDoTim ett = new List<DadosDoTim e>();
while (rd.Read())
{
DadosDoTime ddt = new DadosDoTime();
ddt.pos = 0;
ddt.classificac ao = 0;
tt.Add(ddt);
}


Jon

[Marc Gravell]

Re: Dynamic array

Can you define "its don´t work"?

What happens? Does it error? Or not work as expected?

It sounds like you actually want a List<Tor similar - arrays are (by
definition) fixed size:

List<DadosDoTim ett = new List<DadosDoTim e>();
while(rd.Read() ) {
DadosDoTime newObj = new DadosDoTime();
newObj.pos = 0;
newObj.classifi cacao = 0;
tt.Add(newObj);
}

Marc

[Cleber Schönhofen]

Re: Dynamic array

Compilation error, variable not initializate.
DadosDoTime is a class, how i create a List this ? And how i access this
elements after ?
--
Cleber Schönhofen
Infobola
"Marc Gravell" <marc.gravell@g mail.comescreve u na mensagem
news:uuGe5Z9HJH A.4416@TK2MSFTN GP06.phx.gbl...

Can you define "its don´t work"?
>
What happens? Does it error? Or not work as expected?
>
It sounds like you actually want a List<Tor similar - arrays are (by
definition) fixed size:
>
List<DadosDoTim ett = new List<DadosDoTim e>();
while(rd.Read() ) {
DadosDoTime newObj = new DadosDoTime();
newObj.pos = 0;
newObj.classifi cacao = 0;
tt.Add(newObj);
}
>
Marc

[Jon Skeet [C# MVP]]

Re: Dynamic array

On Sep 26, 2:12 pm, "Cleber Schönhofen" <cleber...@hotm ail.comwrote:

    Compilation error, variable not initializate.

On which line? The only variable you haven't shown as being
initialized is "rd" - which has nothing to do with the array side of
things.

    DadosDoTime is a class, how i create a List this ?

See Marc's code or mine.

And how i access this elements after ?

You can access them by index, or using foreach.

Jon

[Cleber Schönhofen]

Re: Dynamic array

Ok thanks...

--
Cleber Schönhofen
Infobola
"Jon Skeet [C# MVP]" <skeet@pobox.co mescreveu na mensagem
news:5808dadc-a6e9-4027-97aa-1fa5b0ce8ebd@s2 0g2000prd.googl egroups.com...
On Sep 26, 2:12 pm, "Cleber Schönhofen" <cleber...@hotm ail.comwrote:

Compilation error, variable not initializate.

On which line? The only variable you haven't shown as being
initialized is "rd" - which has nothing to do with the array side of
things.

DadosDoTime is a class, how i create a List this ?

See Marc's code or mine.

And how i access this elements after ?

You can access them by index, or using foreach.

Jon

[OD]

Re: Dynamic array

its don´t work :

DadosDoTime[] tt;
int i = 0;
while (rd.Read())
{
tt[i] = new DadosDoTime();
tt[i].pos = 0;
tt[i].classificacao = 0;
i++;
}
>
why ?

because tt[i] is pointing nowhere since tt doesn't exist (the array
itself has not been created, what you're doing ini first version that
is working...)
You're mixing item creation and array creation. Second version of your
code is creating array items, but not the array.

Another point : your code is dangerous because you're using a fixed
length array (100 items) and you're looping within a "while (rd.Read)"
and you can't be sure there are exactly 100 items to read. Perhaps
less, perhaps more. And for the last case your code will crash.
Use a List<DadosDoTim einstead of an array.

--


OD___

https://www.e-naxos.com