|
It works with Borland C/C++ 5.5
|
|
|
|
|
With gcc (version 3.4.4) it doesn't work, i remaining 0 forever.
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
|
|
|
|
|
i wonder what would happen in other languages??
*writes java application*
we've got a Infinite loop here...i=0, all the way  
-st0le [st0le'n'stuff softwarez!]
http://st0lenc0des.googlepages.com/
modified on Tuesday, February 19, 2008 12:24 AM
modified 20-Oct-19 21:02pm.
|
|
|
|
|
Java behaves the same way, i.e. loops indefinitely (or at least, until the hammer comes down).
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
|
|
|
|
|
But not so with
gcc version 3.2 (mingw special 20020817-1)
|
|
|
|
|
C# is the same, so, it seems this behaviour is predictable and I will have to read PIEBALD's lengthy excerpt.
|
|
|
|
|
What's happening makes sense. The operator in question is the postfix incrementor; it increments the variable, but it returns the pre-incrementation value. So, it increments itself, but it's being assigned its original value.
|
|
|
|
|
Isn't the question just whether the runtime environment first assigns the old value. I really thought this would just eventually increment the variable. Because it should normally first assign the old value to i, and then increment i. Why should it ever store the old value somewhere first, then increment i, then put that old value back in i? I know I'm wrong, cuz as said before C# gives an infinite loop, but still it's weird.
|
|
|
|
|
How could it do that? The operator's function has to end (return) before the assignment occurs; that means the incrementation has to happen first.
|
|
|
|
|
liquidplasmaflow wrote: the incrementation has to happen first
says who? the autoincrement is not necessary in the expression evaluation, and hence it can
be scheduled before or after the assignment operator, that is why the net result is undefined.
Luc Pattyn [Forum Guidelines] [My Articles]
This month's tips:
- before you ask a question here, search CodeProject, then Google;
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get;
- use PRE tags to preserve formatting when showing multi-line code snippets.
|
|
|
|
|
C++'s operator ++ is a function. Last I checked, a function can't do anything after it returns 
<br />
int& operator++(int& argument, int)<br />
{<br />
int return_value = argument;<br />
argument += 1;<br />
return return_value;<br />
}<br />
Am I right?
|
|
|
|
|
Hi,
the autoincrement operator may be implemented as a function, I don't
think it has to; in C it typically is not. And even when it is a
function, it could be inlined automatically, and the instructions
then can be rescheduled by the compiler, so there is no way you can
predict which one (the final store, or the autoincrement) will
occur last and hence prevail; all that in accordance with the
legalese language specs PIEBALD showed us.
Luc Pattyn [Forum Guidelines] [My Articles]
This month's tips:
- before you ask a question here, search CodeProject, then Google;
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get;
- use PRE tags to preserve formatting when showing multi-line code snippets.
|
|
|
|
|
I'd be interested to know how early versions of C would handle it.
I expect the increment should happen first (if indeed it's handled by a hardware instruction), then the original value assigned back, yielding the infinite loop.
|
|
|
|
|
I have used dozens of C compilers over the years, most if not all of them did not care about
the ambiguity, but simply evaluated the entire expression including side-effects before storing
the result. It is only with the advent of RISC and advanced instruction scheduling that
things got unclear, and the undefined stuff got introduced.
Anyway, I learned long ago not to write code that would be ambiguous or just difficult to read
and understand, so it never really mattered ... What is the point of studying a page of rules
to make sure something is/isn't ambiguous or undefined, where one could add an intermediate
statement or a pair of parentheses? It isn't APL or Lisp after all.
Luc Pattyn [Forum Guidelines] [My Articles]
This month's tips:
- before you ask a question here, search CodeProject, then Google;
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get;
- use PRE tags to preserve formatting when showing multi-line code snippets.
|
|
|
|
|
It seems assigning the value of an incremented variable to itself overrides the increment operation.
If not, it wouldn't actually matter in which order the operations are executed as the result would be the same:
increment comes first:
i = 0 // i = 0
i++ = 1 // i = 1
i = i // i = 1
result: 1
assignment comes first
i = 0 // i = 0
i = i // i = 0
i++ // i = 1
result: 1
|
|
|
|
|
I agree. If the code would look like this:
a = i++;
Then a would be assigned the value of i and i would be incremented after that, so I would expect in given case that in first iteration i would be assigned value of 0 then i would be incremented. Weird indeed.
modified 19-Nov-18 21:01pm.
|
|
|
|
|
Today, I was reviewing the code of a particular module that a vendor who I had outsourced the product had delivered. There was one interesting line. He is reading input from .NET Cache. Good! He is trying to enhance the performance instead of making a costly remoting call.
He is also making a not null check after getting the elements from cache. It sounds still good right?
Well! Now the fun is; there is nothing to handle when cache is null. When I contacted him for this reckless coding horror, the coolest reply was 'IIS needs to be reset when cache gets emptied'.
Is guillotine available in India?
Vasudevan Deepak Kumar
Personal Homepage
Tech Gossips
A pessimist sees only the dark side of the clouds, and mopes; a philosopher sees both sides, and shrugs; an optimist doesn't see the clouds at all - he's walking on them. --Leonard Louis Levinson
|
|
|
|
|
Vasudevan Deepak K wrote: Is guillotine available in India?
That's too humane. North Korea is always available as a harsher alternative.
ROFLOLMFAO
|
|
|
|
|
another example of promising the earth and cutting quality corners to meet the targets.. its just a case of a "developer" being lazy
|
|
|
|
|
PeterTheGreat wrote: another example of promising the earth and cutting quality corners to meet the targets.. its just a case of a "developer" being lazy
Yes, and probably a you-get-what-you-pay-for kind of thing, too.
"I guess it's what separates the professionals from the drag and drop, girly wirly, namby pamby, wishy washy, can't code for crap types." - Pete O'Hanlon
|
|
|
|
|
This guy walks into a bar and...
|
|
|
|
|
Vasudevan Deepak K wrote: When I contacted him for this reckless coding horror, the coolest reply was 'IIS needs to be reset when cache gets emptied'.
"I guess it's what separates the professionals from the drag and drop, girly wirly, namby pamby, wishy washy, can't code for crap types." - Pete O'Hanlon
|
|
|
|
|
I cant tell you how many of these ive cleaned up in recent months:
if(HttpContext.Current.Cache["someKey"] != null)<br />
{<br />
SomeClass someClass = (SomeClass)HttpContext.Current.Cache["someKey"];<br />
}
The problem being that occasionaly the cache item is expired between lines 1 & 2 leading to rather hard to spot null instance exceptions when trying to use someClass.
|
|
|
|
|
Within one of my company's XSLT document's, I came across the following. Seems to be an XSLT version of a familiar coding horror...
<xsl:for-each select="fl:values/fl:dataItem[@field='fl_name']>
<xsl:if test="position()=1">
Output Here
</xsl:if>
</xsl:for-each>
|
|
|
|
|
From time to time it is necessary for me to code xslt. Each time is a horror.
the horror
the horror
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
