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Christian Graus wrote:
if (myVar = 0 )
will compile and will always set myVar to 0 and evaluate to true.
A typo, I guess Christian... 
The value of the expression "A = B" is the value of A after the assignment, i.e. the value of B. Thus, "myVar = 0" evaluates to 0 and false.
--
Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so. (Douglas Adams)
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both of you got it wrong...
i asked what is the difference between:
if (a==0)
{
}
and
if (0==a)
{
}
and not between:
if (a=0)
{
}
and
if (0=a)
{
}
(notice the extra = sign which makes a big difference)
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Lior Shoval wrote:
both of you got it wrong...
i asked what is the difference between:
if (a==0)
{
}
and
if (0==a)
{
}
Christian did answer that one (although he rationalized a couple of '"''s off ). I merely made it clearer what a = 0 evaluates to.
--
Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so. (Douglas Adams)
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checkout my reply to Johann and try to re-answer.
Thanks.
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They did answer. If you get in the habit of always typing the constant first, the compiler will emit an error message when you mistakenly type one equals ('=') instead of two ('==').
Other than that, the only difference between (a == b) and (b == a) is the order of evaluation.
Software Zen: delete this;
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Thanks.
I was under the impression that it had somthing to do with compiler or preprocessor optimizations...
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That means, that using the first method is better to catch typos like "=" that act like assignments?
regards
modified 12-Sep-18 21:01pm.
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Yes. The people who use that method like it for that reason.
I don't use the method myself, since it reduces the readability of the conditional expression. For example, the expressions (x == 7) and (7 == x) evaluate the same and produce the same result. If you're reading the code, however, the first expression is read as "if x is equal to 7" and the second expression is read as "if 7 is equal to x". The reading of the second expression seems awkward to me. I prefer to think of testing a variable against a constant.
Software Zen: delete this;
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I also prefer the second method (var == 0). dunno why, I just got used to it and find it easier to read.
regards
modified 12-Sep-18 21:01pm.
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I have the same problem. It just feels more natural, and easer to read/write (x==7) instead of (7==x). But good habits (a.k.a constant==variable) are good habits. I keep trying to break this one, but habits are haibts.
Trust in the code Luke. Yea right!
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Unless, of course, you use warning level 4, which will give the compiler warning "warning C4706: assignment within conditional expression" if you try to do if (myVar = 0). This happened only in VC++ 5 or 6, I believe; before that, you had to do the if (0 = myVar) hack to get the compiler to complain.
Best wishes,
Hans
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Hi,
Is there any tool which converts the .pdf file to .ppt file format?
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No, given the nature of .pdf files. (you'll find tons of tools the other way).
The best way to achieve it though is to insert the Adobe ActiveX control in one of the slides.
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Thanks for the reply.
Could you please tell me how to insert the Adobe ActiveX control in the slides?
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Using the mouse and an empty .ppt file, it's Insert \ Object, then browse your folders and search for the AcroFx32.dll (or something like this).
To mimic exactly this by code, you can use the Powerpoint object model. (MSDN for more info).
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Hello,
is it possible to include .cpp files using the #include directive? I want to include an external library into my project, but the library has many files and so I would have to add all cpp-files to my project by hand.
Is something like the following allowed?
#include <extfile1.h>
#include <extfile1.cpp>
#include <extfile2.h>
#include <extfile2.cpp> etc...
-Dominik
_outp(0x64, 0xAD);
and
__asm mov al, 0xAD __asm out 0x64, al
do the same... but what do they do?? 
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I'm pretty sure you can.... as long as the library that you are linking in excludes the same cpp files from its build. Otherwise you'll end up with multiply defined functions and classes in the obj file.
Why can't you just compile and link the library, and include only the headers?
And they still ran faster and faster and faster, till they all just melted away, and there was nothing left but a great big pool of melted butter
"I ask candidates to create an object model of a chicken." -Bruce Eckel
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Yes and No.
I assume you want to import the source files not an external library, which you would just add though your projects settings (make file) and then include the header files in your code.
1) If you just want to add the code/source files to your project then just add them to your work space and include the headers to the code files that access them.
2) If you realy want (or need) to include the code/source files via #include then you do not need to include the header files before those code/source files, since the headers should have been included in the source files them selfs. The 2 problems with including code/source files with #include, (1) you can only include them in only one source file and then use the headers in all other files which may need to access them, (2) you may get multiple definitions because header files in the included files may not have been coded to prevent it. (alright there could be more that 2 problems)
3) Think about it. Basicaly what the preprocessor does is creates 1 big file and then compiles it. This is simplistic, but what it means is that the preprocessor combines your file and the included files in to 1 file before it passes it to the compiler. Therefore, if you include code/source files in each of the files that use them then it is the same as cutting and pasting the contains of those files in to each of those files.
Trust in the code Luke. Yea right!
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Thank you, I will think about it 
-Dominik
_outp(0x64, 0xAD);
and
__asm mov al, 0xAD __asm out 0x64, al
do the same... but what do they do??
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Hello!
I have a problem.
I figured out how to use a database on MDI and SDI applications but how can I use one on a Dialog based application?
I want to get some entries of a database and show them to the user on the dialog ( but I dont want to use a SDI or MDI based application... just a dilog based application )... I tried to add a RecordSet and a Recordview on my own and choose a database for it but it gave me some errors...
I already looked the MSDN but I didnt find anything about it ...
Can someone help me?
Please  ...
I thank you for your answers...
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The simplest way is to use DBGrid and then make its dataSource property point to the database.
// Afterall I realized that even my comment lines have bugs
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MSDN introduces how to customize print dialog,but how to customize print setup dialog?
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In my program:
CString str;
CRect rect;
pDC->DrawText(str,&rect,DT_TOP|DT_WORDBREAK);
If the string is too long,It can be displayed in many lines.
I want to change the system row spacing.How can I do?
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You'll have to change the font. Look up the LOGFONT structure in the MSDN.
Software Zen: delete this;
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