C / C++ / MFC

Re: what is the difference of “class instance” and “object”？

24-Oct-08 16:46

An object is an instance of a class.

"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

WangZHua25-Oct-08 0:42

WangZHua

25-Oct-08 0:42

then， why does rational rose has two concepts：“object” and “class instance”？

Re: what is the difference of “class instance” and “object”？

Nemanja Trifunovic25-Oct-08 15:30

Nemanja Trifunovic

25-Oct-08 15:30

WangZHua wrote:
why does rational rose has two concepts

Rational Rose is one of the most irrational pieces of software I have ever tried.

Programming Blog

utf8-cpp

Re: what is the difference of “class instance” and “object”？

David Crow27-Oct-08 2:48

Re: what is the difference of “class instance” and “object”？

27-Oct-08 2:48

I can't speak of another's opinion. Perhaps you should ask them.

"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

Subrat 470826624-Oct-08 22:56

Subrat 4708266

24-Oct-08 22:56

Both are same if that object is of that class.
It will be different if object is a structure object.BCZ in structure bydefault data members are public where in class it is private.
In C structre---------->variable
C++ it will be considered as object.

Re: what is the difference of “class instance” and “object”？

WangZHua25-Oct-08 0:54

WangZHua

25-Oct-08 0:54

all right,but,i think it is not perfect.

i think,object is the description of class，instance is the dynamic concept.
the method of object is description of class 's behaviour.
the method of instance is description of module ‘s behaviour.

is not it？

Re: what is the difference of “class instance” and “object”？

Bram van Kampen25-Oct-08 16:51

Bram van Kampen

25-Oct-08 16:51

What language are you trying to disect.

An object is a lump of data that can be managed by a single handle, by whatever means, either by knowing th precice interpretation of the object, or by knowing how to handle it from the 'outside', and accessing it because you know it's type. A Class is a CPP construct, it is a Prototype, or blueprint of a cpp object.
an Instance (of a class or type) is an actual variable of the type, and as such, an object. All cpp instances are objects, Not every object is a CPP class instance. If you understand the underlying ideas, the distinction becomes trivial, and at the same time futile!

Smile | :)

Bram van Kampen

Re: what is the difference of “class instance” and “object”？

CPallini25-Oct-08 0:24

CPallini

25-Oct-08 0:24

WangZHua wrote:
“class instance”

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]

Finding LAN Addresses and Names

Bram van Kampen24-Oct-08 14:58

Bram van Kampen

24-Oct-08 14:58

Is there an API to find the LAN address, (e.g, 10,1,10,4)on a very small peer to peer network (i.e. No DNS Service explicitly provided), and is there a way of associating such addresses to a Name.

regards,

Bram van Kampen

Re: Finding LAN Addresses and Names

David Crow24-Oct-08 16:10

Re: Finding LAN Addresses and Names

24-Oct-08 16:10

What about NetServerEnum()?

"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

Bram van Kampen25-Oct-08 16:13

Bram van Kampen

25-Oct-08 16:13

thanks,

Going to try that tomorrow. Looks promising.

Smile | :)

Bram van Kampen

Message Maps and SDI

BobInNJ24-Oct-08 11:06

BobInNJ

24-Oct-08 11:06

I typed in an example from the book "MFC Programming from the Ground Up", Second Edition. This example is the first example that shows an SDI application. On of the classes defined in the application is CSampleDoc which is derived from CDocument. They specify the following message map:

<br />
// This is the document's message map.<br />
BEGIN_MESSGAE_MAP( CSampleDoc, CDocument )<br />
	ON_COMMAND( IDM_UNDO, OnUndo )<br />
	ON_COMMAND( IDM_RESET, OnReset )<br />
	ON_COMMAND( IDM_HELP, OnHelp )<br />
END_MESSAGE_MAP()<br />

However, it does not compile and the error message from the compiler is that CDocument is an abstract class. I check the documentation and CDocument is an abstract class. However, I do not understand why this is a problem? Also, is it not normal when writing an SDI application to have a message map for the class derived from CDocument to handle Menus?

Thanks
Bob

Re: Message Maps and SDI

BobInNJ24-Oct-08 11:30

BobInNJ

24-Oct-08 11:30

The problem here is that my typing is poor and my proof reading is less than ideal. The above code
fragment works if you spell BEGIN_MESSAGE_MAP correctly. It does not work if you spell it incorrectly.

Bob

Re: Message Maps and SDI

Mark Salsbery24-Oct-08 12:10

Mark Salsbery

24-Oct-08 12:10

BobInNJ wrote:
works if you spell BEGIN_MESSAGE_MAP correctly. It does not work if you spell it incorrectly

Good to know! Poke tongue | ;-P

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: Message Maps and SDI

CPallini24-Oct-08 23:58

CPallini

24-Oct-08 23:58

Mr.Univoter is a humorless guy.

C++ Profiling...

Drew Stainton24-Oct-08 8:33

24-Oct-08 8:33

I'm usually doing C# work these days, but today I have to track down what's dragging down a C++ app I work on from time to time.

Anyone got the low-down on a good C++ profiler, free or otherwise?

I've checked out VTune from Intel. It looks really good, but the $699 price tag is a little steeper than I was hoping for.

So, any thoughts?

Cheers,
Drew.

David Crow24-Oct-08 9:52

24-Oct-08 9:52

Visual Studio 6 has one.

"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

Drew Stainton24-Oct-08 9:59

24-Oct-08 9:59

I only have VS2008 Pro. My understanding was the the profiler only comes with Team System. Perhaps I'm wrong?

Cheers,
Drew.

David Crow24-Oct-08 10:05

24-Oct-08 10:05

Drew Stainton wrote:
Perhaps I'm wrong?

It doesn't look like it.

"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

Drew Stainton24-Oct-08 12:25

24-Oct-08 12:25

I've gone with Very Sleepy[^] for today. Not great, but free and does what I need right now. I'll look for something more permanent later.

Cheers,
Drew.

Joe Woodbury24-Oct-08 12:14

Joe Woodbury

24-Oct-08 12:14

I haven't tried it yet, but AQTime looks good. (I'm going to download the demo next week--don't feel like starting something new on Friday afternoon.)

http://www.automatedqa.com/products/aqtime/[^]

Anyone who thinks he has a better idea of what's good for people than people do is a swine.
- P.J. O'Rourke

Drew Stainton24-Oct-08 12:26

24-Oct-08 12:26

Thanks Joe. I hadn't come across that one yet. I'll take a look. Looks more comprehensive than the others as it'll do .Net stuff as well.

Cheers,
Drew.

Cedric Moonen24-Oct-08 21:46

Cedric Moonen

24-Oct-08 21:46

I used it before and it helped us a lot to track memory leaks and finding bottlenecks in our code. And it is also quite easy to work with it.

Cédric Moonen
Software developer

Charting control [v1.5]
OpenGL game tutorial in C++

Drew Stainton25-Oct-08 5:19