Re: Array Variable initialization [modified] - C / C++ / MFC Discussion Boards

can you show your constructor please ?

T.RATHA KRISHNAN wrote:
TModels[1](0);

this line makes absolutely no sense, and i don't even know what you're trying to achieve with this.

BTW, can't you just use the STL ans its containers ?

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Thanks. I've corrected this error myself.

and for the benefit of everyone, will you share this with us ?

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Oh! With Pleasure!
First I initialized the array elements like this:

TestAI::TestAI() //Constructor
     TModels[1](0)
   , TModels[2](0)
   , TModels[3](0)
{

}

and now I change it to the following:

TestAI::TestAI() //Constructor
{
  TModels[1] = 0;
  TModels[2] = 0;
  TModels[3] = 0;

}

and the errors vanished.

why don't you just do this :

TModel = {0};

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Because it doesn't work?
For instance

int a[50] = {0};

Doesn't produce the result I'm expecting (it initializes only the first array element).
Am i wrong?

Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

CPallini wrote:
Am i wrong?

you are, or the compiler is !

the standard says that such a construction (when initializing a variable at the same time than declaration) initializes every element of the array to their default value.

I'm even pretty sure Nemanja Trifunovic quoted me somewhere about that...

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toxcct wrote:
you are, or the compiler is !

Maybe the latter:
the program:

#include <iostream>
using namespace std;

void main()
{
  const int N = 10;
  int a[N]={7};

  for (int i=0; i<N;i++)
  {
    cout << a[i] << endl;
  }
}

the output:

The system:
Visual C++ 2008 Express Edition running on Win XP.

Eventually YOU may be wrong! Poke tongue | ;-P

(actually I'm quite confident you're right, but don't use it unless you really want surprises!)

[added]
Actually I think VS2008 cannot be so out-of-the-standard.
I suppose the standard establishing that, whenever the initialization list is too short, the remaining array
items are default-initialized (to 0 if integers).
[/added]

Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

modified on Tuesday, September 9, 2008 11:53 AM

Same output with Visual C++ 6.0, WinXP SP2 Smile | :)

Surprising.. Confused | :confused:

Regards,
Sandip.

SandipG wrote:
Same output with Visual C++ 6.0

Visual C++ is not what a decent programmer call a standard compliant compiler, Sir !

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IMHO such a discrepancy would be too gross, even for VC6.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

yes, probably, but it's not *THE* compiler to test the standard ! Wink | ;)

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CPallini wrote:
(it initializes only the first array element).

Not according to the STOSx instructions. Of course, I only use it to initialize POD types to 0. Otherwise, I'd use memset().

"Love people and use things, not love things and use people." - Unknown

"The brick walls are there for a reason...to stop the people who don't want it badly enough." - Randy Pausch

Sorry no STOS here:

...
  const int N = 10;
  int a[N]={7};
00401003  xor         eax,eax 
00401005  push        esi  
00401006  mov         dword ptr [esp+8],7 
0040100E  mov         dword ptr [esp+0Ch],eax 
00401012  mov         dword ptr [esp+10h],eax 
00401016  mov         dword ptr [esp+14h],eax 
0040101A  mov         dword ptr [esp+18h],eax 
0040101E  mov         dword ptr [esp+1Ch],eax 
00401022  mov         dword ptr [esp+20h],eax 
00401026  mov         dword ptr [esp+24h],eax 
0040102A  mov         dword ptr [esp+28h],eax 
0040102E  mov         dword ptr [esp+2Ch],eax 
...

(Visual C++ 2008 Express Edition, Win XP).
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

CPallini wrote:
00401003 xor eax,eax

Look two lines up from this one and you should find:

rep stosd

"Love people and use things, not love things and use people." - Unknown

"The brick walls are there for a reason...to stop the people who don't want it badly enough." - Randy Pausch

No luck (there isn't such insruction). On the other hand, the output of this program [^] confirms my assumption.
See also Sandip's post [^].
I should admit I was very surprised by such a behaviour.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

and what about {0} instead of {7}, and in Release Mode, not in Debug Mode ?

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See my added remark here [^].

BTW my tests were of course performed both in Debug and the Release mode.
Poke tongue | ;-P

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

toxcct wrote:
...and what about {0} instead of {7}...

0 works fine.

toxcct wrote:
...and in Release Mode, not in Debug Mode ?

Same results for both 0 and 7. This is why I only do it when setting things to 0. I use memset() otherwise.

"Love people and use things, not love things and use people." - Unknown

"The brick walls are there for a reason...to stop the people who don't want it badly enough." - Randy Pausch

DavidCrow wrote:
0 works fine.

It is just a side-effect of default (int) initialization: you're actually initializing only the first array item. Try the following code:

#include <iostream>
using namespace std;

struct MyStruct
{
  MyStruct():_i(-1), _j(0),_k(-1){ }
  MyStruct(int a):_i(a), _j(a), _k(a){ }
  int _i,_j,_k;
};



void main()
{
  int i;
  MyStruct a[5] = {0};
  for (i=0; i<5; i++)
  {
    cout << i << ") {" << a[i]._i << ", " << a[i]._j  <<", " << a[i]._k << "}" << endl;
  }
}

DavidCrow wrote:
This is why I only do it when setting things to 0. I use memset() otherwise.

The above is a wise approach.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

For structs, I'd use memset(). I only use 0 for POD types.

"Love people and use things, not love things and use people." - Unknown

"The brick walls are there for a reason...to stop the people who don't want it badly enough." - Randy Pausch

DavidCrow wrote:
For structs, I'd use memset(). I only use 0 for POD types.

That's good.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

I think you are trying to do something like this..

class A{
int TModels[3];
public:
A():TModels[1](0){}
};
int main(){
A a;
}
which is giving you above error:

As per my knowledge there is no (standard) C++ way of doing this. Array initializers do not exist for classes. So prob you can do it somewhat like this:

class A{
int TModels[3];
public:
A(){
for(int i=0; i<3; i++)
TModels[i] = 0;
}
};
int main(){
A a;
}

Hope it helps you

Thanks. I've already corrected that.

Hi,

I am writing a client application to connect to servers that have shares information.
I found out that servers will not allow data to be sent via different sockets after login from one socket.

So, I think asynchronous model using the same socket to communicate with the server for the requests should work. Here I am planning to use a separate thread for each request.

Here, if 2 threads are present and each send diff requests. Now server sends the responses. When checked with this model, the responses were received by each thread were not theirs. (this might be because both the threads are receiving on the same socket.)

Here, my question is how to know that the message received doesnt belong it OR how to make the thread receive the response to the request it posted?

Please help on this ASAP, its urgent.

Many thanks in advance.

Mohan t working for N.I.C