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But delete and delete[] both seem to generate the same assembly output, so is there really a difference ? 
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They may look the same, but they're not.
For instance, take this simple application:
#include "stdafx.h"
#include <iostream>
using namespace std;
class a
{
public:
a(){};
~a(){cout << "a::~a()\n";};
};
int main(int argc, char* argv[])
{
a *pa = new a[10];
delete [] pa;
cout << "------" << endl;
pa = new a[10];
delete pa;
return 0;
}
If your theory were correct, it would output 10 a::~a()'s followed by dashes and 10 more. Instead, this is the output:
a::~a()
a::~a()
a::~a()
a::~a()
a::~a()
a::~a()
a::~a()
a::~a()
a::~a()
a::~a()
------
a::~a()
As you can see, the destructor gets called 10 times when using delete [] and only once when using delete.
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Delete[] is necessary for deletion of objects. I mean instances of classes.
Objects in array should be garanteed to destruct itself and free resource.
Delete[] calls all of destructor of objects in array and call of destructor
calls destructor of base class's destructor.
So delete[] gaurantees destruction of all object in array .
For primitive types like int, long, char etc..
You don't have use delete[] for freeing resource.
Delete is enough. But this is only the theory..
In practice,I recommend to use delete[] whenever you're freeing resource in array.
Cause it makes code more clear and readable.
It looks to clear to other developers who are seeing your code or youself in future.
Regards,
Ryan
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Okay, this is kinda weird ...
I'm going to simplify it (but still show problem)
=================================================
char *ModuleList[10];
char *strInput;
char buffer[80] = {80};
bool bDone = false;
int iLoop = 0;
while (!bDone)
{
strInput = _cgets(buffer);
if (strcmp(strInput, "exit") == 0) { bDone = true; }
else
{
ModuleList[iLoop] = strInput;
iLoop++;
}
}
Now yeah iLoop will go higher than 9 that will cause an error .. but the problem is that the ModuleList array does this:
Input: test
ModuleList[0] == test;
ModuleList[1] == "";
..
Input: again
ModuleList[0] == "again";
ModuleList[1] == "again";
ModuleList[2] == ""
..
See what I mean? why does it change the previous values in the array instead of leaving them alone? The array seems to get screwed up when the strInput = _cgets(buffer); line gets called.
Any help here is much appreciated .. probably some stupid mistake, but I'm a little lost here
Thanks, Travis
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strInput is always has the same value (buffer+2). so, you are setting the same pointer value into each ModuleList element.
-c
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also the line char buffer[80] = {80}; should read char buffer[82] = {80};
just a small point
"every year we invent better idiot proof systems and every year they invent better idiots"
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Where you have:
char *ModuleList[10];
it is NOT an array of strings!!
It is actuall an array of string pointers.
So where you go:
ModuleList[iLoop] = strInput;
what you actually doing is setting all of the string pointers in the array to
point to the same string. The same string that you change every time around
the loop.
So if you really want to store the strings try:
char ModuleList[10][80];
and
(void)strncpy(ModuleList[iLoop], strInput, 80-1);
ModuleList[iLoop][80] = NULL; // to guarentee NULL termination.
// in stead of ModuleList[iLoop] = strInput;
Hope that helps.
Jules
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Thanks for the help from you 3, helped a lot and I have it working now =)
- Travis
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I want to learn how to program a simple Databases.
What Database can i learn most from when am new??
I was thinking of making a simple text in a editbox and save it on a base,
where do i start??? Thank you 
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<<< In the name of GOD >>>
Hi.
I want to get string from Owner-Draw ListBox :
void CHlistbox::DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct)
{
CString string;
CDC *pDC = CDC::FromHandle(lpDrawItemStruct->hDC);
CRect rc = lpDrawItemStruct->rcItem;
UINT action = lpDrawItemStruct->itemAction;
UINT state = lpDrawItemStruct->itemState;
UINT index = lpDrawItemStruct->itemID;
if(action & ODA_DRAWENTIRE)
{
GetText(index,string);
pDC->FillSolidRect(rc,RGB(0,0,0));
pDC->SetTextColor(RGB(100,100,50));
pDC->TextOut(rc.left+1, rc.top+1, string); // PROBLEM IS THERE
}
}
Adding string with ListBox :
void TestDlg::OnOK()
{
m_listbox.AddString("Hadi Rezaie");
}
My other problem is when i added 1 string, i cant adding other string with ListBox.
Please help me ...
Hadi Rezaie
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Is there a way to get a handle or a pointer to the scroll bar in a CListCtrl ?
Is there a way to disable and make the scroll bar in the CListCtrl class not appear?
Death reaches all
Your time will come billy boy
Eyal
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Hallo everybody! I'm developing an application with other people and we are using components.
I'm developing some components and I would like to know if someone know if it's possible (or how) to choose dynamically the ID for the new component at runtime.
Thanks
Bye bye
Nicola
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as far as i know the resource id's are a compile time thing that you would have a real hard time changing at run time ... its important to understand the difference between compile time and run time ... what you can and cant do
unless of course i dont understand what i'm talking about
always possible 
"every year we invent better idiot proof systems and every year they invent better idiots"
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You need to get with your fellow developers and standardize on a method to generate ID's. Basically, all you need to do is make sure that you don't duplicate the same number on the same dialog. One way to do this is allocate a range of ID's that you never use for static resources, and then create a function to allocate the ID's at runtime, which is simply a counter that returns a new number in the range everytime it's called.
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First, I think you read this writings.
I want to know how to get ip address and customer id(client id).
so, I want to put in data(CString variables) value made from above structure.
I don't know this at all.
Please reply this question quickly.
Please... Please...
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WSADATA wsaData;
struct sockaddr_in sock;
CString strHostname;
int lLen = 255;
WSAStartup(0x0101, &wsaData);
gethostname(strHostname.GetBuffer(lLen), lLen);
HOSTENT * lpHost = gethostbyname(strHostname.GetBuffer(lLen));
memcpy(&(sock.sin_addr), lpHost->h_addr_list[0], lpHost->h_length);
TRACE2 ("Host Name: %s IP address : %s\n",strHostname, inet_ntoa(sock.sin_addr));
WSACleanup();
Considderd to be the worlds fastest knoppenbonker.
10 Months of working experience with the worlds fastest copie paster(about 2000 lines a minute).
And experience with the one and only NewEra Guru.
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I'm using CDataSource, CSession etc to work with some database.
This database is having, for example, one table with two columns.
One is a self-incrementing counter (index) and other is a value.
My task is to write a function like this:
long Add(long val) {
return index_of_val_added;
}
I'm doing it this way:
long Add(long val) {
CCommand< CAccessor< table > > t;
t.Open(session, "insert into table(val) values(-1);", NULL, NULL, DBGUID_DEFAULT, FALSE);
t.Close();
t.Open(session, "select * from table where val=-1;");
int id = t.m_id;
t.Close();
CString s;
s.Format("update table set val=%d where id=%d", val, id);
t.Open(session, s, NULL, NULL, DBGUID_DEFAULT, FALSE);
t.Close();
return id;
}
I know, that it is ugly... Could anybody show me the correct way to do it?
With the best regards, Vitaly.
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I have a JPEG image to be printed onto the printer.How to this is possible in Windows NT
Raja sekhar
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Use one of the classes available online ( like www.paintlib.de ) to load the image, then you'll be able to print it just like a BMP.
Christian
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I've defined a private message in my MainFrm.h as below:
#define UWM_USER_APPLY WM_APP+17
afx_msg LRESULT OnUserApply(WPARAM wparam, LPARAM lparam);
In MainFrm.cpp, I've added this within the message-map macro:
ON_MESSAGE(UWM_USER_APPLY,OnUserApply)
I've created a property sheet, when user press "Apply" button, I do the following:
void COptionSheet::OnApply(){
GetActivePage()->UpdateData();
HWND hwnd=AfxGetMainWnd()->m_hWnd;
::SendMessage(hwnd,UWM_USER_APPLY,(WPARAM)this,0);
m_pg1.SetModified(FALSE);
m_pg2.SetModified(FALSE);
}
It work fine at debug version, when I build the release version, it'll cause "illegal operation" at the line:
::SendMessage(hwnd,UWM_USER_APPLY,(WPARAM)this,0);
If I simply changed it to a standard WM_, it'll work. For example:
::SendMessage(hwnd,WM_ENABLE,(WPARAM)this,0);
I'm using Visual C++ 6.0 with SP4 on Win98. I've tried both in NT and Win98, both have the same bad result.
Please help. Thanks in advance.
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I've seen this happen recently - pretty much the same thing you are doing.
First 'workaround' I found was to change the macro to ON_COMMAND - which in my case didn't make a lot of sense, since my message was not a user command.
I ended up sending the message to another window and that seemed to work as a WM_MESSAGE.
I've also seen it land on the illegal instruction code (in nn, I believe) when you add a handler method and leave out a required parameter declaration (e.g. OnMyMessage() instead of OnMyMessage(UINT num)
And, as you say, only in release. Sigh... aren't macros wonderful?
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If I had an app that used Winsock, how would I SOCKS-enable it? Any good tutorials? Thanks in advance...
--
Pikapika,
Capt. Jean-Luc Pikachu
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The following C version works fine.
/* C Version */
#include conio.h
#include stdio.h
int main ()
{
char ch;
printf ("Type a character: ");
ch = getch();
printf ("\nYou typed: %c\n", ch);
return 0;
}
However the C++ version does not work the same way. After typing a key, I have to press the enter key to get the program going.
/* C++ version */
#include iostream
using std::cout;
using std::cin;
int main ()
{
char ch;
cout << "Type a character: ";
cin.get(ch);
// ch = cin.get();
cout << "You typed: " << ch << "\n";
return 0;
}
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It's a messed up question with a fairly messed up answer. If you're in Windows, the iostream libraries may not work the happy way you want. That's the easy copout answer.
The longer answer (page 72 of the March 2001 issue of C/C++ User's Journal, an EXCELLENT magazine) says that you have to go down below istream/ostream to the std::streambuf class. You'll want to look for streambuf::sbumpc as a possible solution to your problem.
Unfortunately, my expertise is in VBScript (ASP 2.0) and PHP, and my attempts to use C/C++ usually make me scream stuff that would get my booted from this board. But I HAVE had the same sort of problems you've had, you're not alone, and the solution is non-obvious. That, and I didn't fully understand enough of the article to explain it to you. Check out the magazine (http://www.cuj.com/) and good luck.
--
Pikapika,
Capt. Jean-Luc Pikachu
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Can I just second that CUJ is a fine, fine mag, ( although my March isue has not yet arrived as I am in Australia ), and that you should subscribe.
Christian
The content of this post is not necessarily the opinion of my yadda yadda yadda.
To understand recursion, we must first understand recursion.
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