if(x=5)
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The "best practice" in writing comparisons like this is to put the constant on the LHS, so, instead of "if (x = 5)", you write "if (5 = x)", the compiler will flag the latter as an error. I think I read this trick in one of the Microsoft Programmer's Guides, many many years ago.
-- God creates; man programs.
Yeah, like I said, that's what I did after that.
Christian Graus - Microsoft MVP - C++ Metal Musings - Rex and my new metal blog
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Ravi beat me to it, but this is the first thing that comes to mind. I'd been coding C++ for about 8 months, paid employment for about 2. I spent a day looking for this bug, every time I saw the line if (x=5) my brain just turned it in to if (x==5) which is obviously what I meant. I got into the habit of writing if (5 == x ) after that, and every now and again, I'd get the compiler error that told me I'd made the same typo again :-)
Christian Graus - Microsoft MVP - C++ Metal Musings - Rex and my new metal blog
I always compile at warning level 4 so code like this will generate warning C4706: 'assignment within conditional expression'. So I view this more as a typo than a bug.
You may be right
I may be crazy
-- Billy Joel --Within you lies the power for good, use it!!!
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Ravi beat me to it, but this is the first thing that comes to mind. I'd been coding C++ for about 8 months, paid employment for about 2. I spent a day looking for this bug, every time I saw the line if (x=5) my brain just turned it in to if (x==5) which is obviously what I meant. I got into the habit of writing if (5 == x ) after that, and every now and again, I'd get the compiler error that told me I'd made the same typo again :-)
Christian Graus - Microsoft MVP - C++ Metal Musings - Rex and my new metal blog
Christian Graus wrote:
I got into the habit of writing if (5 == x )
I don't like that but it's quite common and is one reason (amomg many) why, in the newer languages, we shouldn't still be using C-syntax three decades after it was first devised. Still, I don't make this particular mistake. Maybe it's just the way my mind works. (I make all sorts of other mistake of course.:))
Kevin
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Ravi beat me to it, but this is the first thing that comes to mind. I'd been coding C++ for about 8 months, paid employment for about 2. I spent a day looking for this bug, every time I saw the line if (x=5) my brain just turned it in to if (x==5) which is obviously what I meant. I got into the habit of writing if (5 == x ) after that, and every now and again, I'd get the compiler error that told me I'd made the same typo again :-)
Christian Graus - Microsoft MVP - C++ Metal Musings - Rex and my new metal blog
VB ::-> , atleast VB can sit straight now in this thread. lol btw, if(5==x):omg: My eyes are getting swapped automatically to make it (x==5). I've been trapped by the "=" for few times , but I've become more cautious on this.
--[:jig:]-- [My Current Status] Link2006 wrote:Let's take it outside of CP Jeremy : Please don't.I would love to see this.I'm making the popcorn already.
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I always compile at warning level 4 so code like this will generate warning C4706: 'assignment within conditional expression'. So I view this more as a typo than a bug.
You may be right
I may be crazy
-- Billy Joel --Within you lies the power for good, use it!!!
In C# if statments can only evaluate booleans so if(x=5) would not give it a boolean and cause a compiler error. C# is the way of the future.
static int Sqrt(int x) { if (x<0) throw new ArgumentOutOfRangeException(); int temp, y=0, b=0x8000, bshft=15, v=x; do { if (v>=(temp=(y<<1)+b<>=1)>0); return y; :omg:
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In C# if statments can only evaluate booleans so if(x=5) would not give it a boolean and cause a compiler error. C# is the way of the future.
static int Sqrt(int x) { if (x<0) throw new ArgumentOutOfRangeException(); int temp, y=0, b=0x8000, bshft=15, v=x; do { if (v>=(temp=(y<<1)+b<>=1)>0); return y; :omg:
Henize wrote:
C# is the way of the future.
Yeah, sure. VB uses context to determine which meaning for "=" you want. Is VB the way of the future? I'm with PJ on this one - it should produce a warning. that's just... The C++ Way.
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Henize wrote:
C# is the way of the future.
Yeah, sure. VB uses context to determine which meaning for "=" you want. Is VB the way of the future? I'm with PJ on this one - it should produce a warning. that's just... The C++ Way.
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VB is crap. C# allows flexable syntax and more power with pointers. I guess I should say .NET is the way of the future.
static int Sqrt(int x) { if (x<0) throw new ArgumentOutOfRangeException(); int temp, y=0, b=0x8000, bshft=15, v=x; do { if (v>=(temp=(y<<1)+b<>=1)>0); return y; :omg:
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Ravi beat me to it, but this is the first thing that comes to mind. I'd been coding C++ for about 8 months, paid employment for about 2. I spent a day looking for this bug, every time I saw the line if (x=5) my brain just turned it in to if (x==5) which is obviously what I meant. I got into the habit of writing if (5 == x ) after that, and every now and again, I'd get the compiler error that told me I'd made the same typo again :-)
Christian Graus - Microsoft MVP - C++ Metal Musings - Rex and my new metal blog
Hmm. I know you all use Visual C. Though I seldom make this mistake, Borlands C++Builder compiler gives me a neat warning: 'Possibly incorrect statement.:cool:'
Cees Meijer Software / Hardware Engineer QMetrix BV Specialists in River and Sea flow measurements.
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Christian Graus wrote:
I got into the habit of writing if (5 == x )
I don't like that but it's quite common and is one reason (amomg many) why, in the newer languages, we shouldn't still be using C-syntax three decades after it was first devised. Still, I don't make this particular mistake. Maybe it's just the way my mind works. (I make all sorts of other mistake of course.:))
Kevin
*grin* I don't believe I've ever made it except as a typo. Yeah, I have abandoned that syntax in C#, as it's no longer necessary.
Christian Graus - Microsoft MVP - C++ Metal Musings - Rex and my new metal blog
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Hmm. I know you all use Visual C. Though I seldom make this mistake, Borlands C++Builder compiler gives me a neat warning: 'Possibly incorrect statement.:cool:'
Cees Meijer Software / Hardware Engineer QMetrix BV Specialists in River and Sea flow measurements.
So does VC on a level 4. I should mention, I took this job on a project that had been around for some time, and when I started, there were 600 warnings or something. This was the event that finally helped me convince my boss to let me clear all those warnings, and impliment a 'warnings are errors' policy.
Christian Graus - Microsoft MVP - C++ Metal Musings - Rex and my new metal blog
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Ravi beat me to it, but this is the first thing that comes to mind. I'd been coding C++ for about 8 months, paid employment for about 2. I spent a day looking for this bug, every time I saw the line if (x=5) my brain just turned it in to if (x==5) which is obviously what I meant. I got into the habit of writing if (5 == x ) after that, and every now and again, I'd get the compiler error that told me I'd made the same typo again :-)
Christian Graus - Microsoft MVP - C++ Metal Musings - Rex and my new metal blog
Christian Graus wrote:
if (x=5)
Hasn't everyone* made this same mistake at one point in time? :doh: Not really wanting to admit this has happened to me on at least two occasions.
I'd love to help, but unfortunatley I have prior commitments monitoring the length of my grass. :Andrew Bleakley:
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Ravi beat me to it, but this is the first thing that comes to mind. I'd been coding C++ for about 8 months, paid employment for about 2. I spent a day looking for this bug, every time I saw the line if (x=5) my brain just turned it in to if (x==5) which is obviously what I meant. I got into the habit of writing if (5 == x ) after that, and every now and again, I'd get the compiler error that told me I'd made the same typo again :-)
Christian Graus - Microsoft MVP - C++ Metal Musings - Rex and my new metal blog
Christian Graus wrote:
if (5 == x )
I've done this for years (after running into that bug a couple times in college and spending days trying to track it down). Interestingly enough, I've run into opposition to it from supervisors when coding standards are discussed. I've never quite understood why they wouldn't want to avoid possible bugs, but sometimes they are almost religious about it.
If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week Zac
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In C# if statments can only evaluate booleans so if(x=5) would not give it a boolean and cause a compiler error. C# is the way of the future.
static int Sqrt(int x) { if (x<0) throw new ArgumentOutOfRangeException(); int temp, y=0, b=0x8000, bshft=15, v=x; do { if (v>=(temp=(y<<1)+b<>=1)>0); return y; :omg:
Henize wrote:
In C# if statments can only evaluate booleans so if(x=5) would not give it a boolean and cause a compiler error.
Which it "borrowed" from Java ...
Henize wrote:
C# is the way of the future.
Just like you don't use a hammer when you need a screwdriver, you don't use C# (or Java or VB) when you need C++.
If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week Zac
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Christian Graus wrote:
if (5 == x )
I've done this for years (after running into that bug a couple times in college and spending days trying to track it down). Interestingly enough, I've run into opposition to it from supervisors when coding standards are discussed. I've never quite understood why they wouldn't want to avoid possible bugs, but sometimes they are almost religious about it.
If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week Zac
Zac Howland wrote:
nterestingly enough, I've run into opposition to it from supervisors when coding standards are discussed. I've never quite understood why they wouldn't want to avoid possible bugs, but sometimes they are almost religious about it.
I don't especially like this style but it's not the kind of thing I would forbid in a coding standard. It should concentrate on more important things, e.g., in C/C++, uninitialised variables.
Kevin
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Zac Howland wrote:
nterestingly enough, I've run into opposition to it from supervisors when coding standards are discussed. I've never quite understood why they wouldn't want to avoid possible bugs, but sometimes they are almost religious about it.
I don't especially like this style but it's not the kind of thing I would forbid in a coding standard. It should concentrate on more important things, e.g., in C/C++, uninitialised variables.
Kevin
Kevin McFarlane wrote:
It should concentrate on more important things, e.g., in C/C++, uninitialised variables.
Agreed. However, it is interesting what topics actually get fought over most when discussing coding standard guidelines. I've been in meetings with 2 different development teams at 2 different companies and had similar discussions over what I consider to be rather trivial issues.
If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week Zac
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Ravi beat me to it, but this is the first thing that comes to mind. I'd been coding C++ for about 8 months, paid employment for about 2. I spent a day looking for this bug, every time I saw the line if (x=5) my brain just turned it in to if (x==5) which is obviously what I meant. I got into the habit of writing if (5 == x ) after that, and every now and again, I'd get the compiler error that told me I'd made the same typo again :-)
Christian Graus - Microsoft MVP - C++ Metal Musings - Rex and my new metal blog
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Zac Howland wrote:
nterestingly enough, I've run into opposition to it from supervisors when coding standards are discussed. I've never quite understood why they wouldn't want to avoid possible bugs, but sometimes they are almost religious about it.
I don't especially like this style but it's not the kind of thing I would forbid in a coding standard. It should concentrate on more important things, e.g., in C/C++, uninitialised variables.
Kevin
[coding standards]
Kevin McFarlane wrote:
It should concentrate on more important things
Like which ways brackets should be placed! :mad: Hating coding style guides and the people that are content in contriving them
"We trained hard, but it seemed that every time we were beginning to form up into teams we would be reorganised. I was to learn later in life that we tend to meet any new situation by reorganising: and a wonderful method it can be for creating the illusion of progress, while producing confusion, inefficiency and demoralisation." -- Caius Petronius, Roman Consul, 66 A.D.
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Ravi beat me to it, but this is the first thing that comes to mind. I'd been coding C++ for about 8 months, paid employment for about 2. I spent a day looking for this bug, every time I saw the line if (x=5) my brain just turned it in to if (x==5) which is obviously what I meant. I got into the habit of writing if (5 == x ) after that, and every now and again, I'd get the compiler error that told me I'd made the same typo again :-)
Christian Graus - Microsoft MVP - C++ Metal Musings - Rex and my new metal blog
Christian Graus wrote:
if (5 == x )
Actually, there is quite some resistence to this. Their justification is that you don't avoid bugs by tricks or writing unreadable code. You happen to have such a trick for this case, but many other bugs cannot be avoided by tricks. Sticking to a good discipline is the key. The good thing is when you think of that trick, you are avoiding the bug already, regardless of which way you actually code. :)
Best, Jun
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Kevin McFarlane wrote:
It should concentrate on more important things, e.g., in C/C++, uninitialised variables.
Agreed. However, it is interesting what topics actually get fought over most when discussing coding standard guidelines. I've been in meetings with 2 different development teams at 2 different companies and had similar discussions over what I consider to be rather trivial issues.
If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week Zac
Zac Howland wrote:
I've been in meetings with 2 different development teams at 2 different companies and had similar discussions over what I consider to be rather trivial issues.
Guidelines I've come across usually split into recommended and mandatory. Then the things which people disagree over are put in recommendations. But really guidelines, e.g., for C++, should concentrate on the kind of stuff in Scott Meyers's Effective C++ books.
Kevin
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[coding standards]
Kevin McFarlane wrote:
It should concentrate on more important things
Like which ways brackets should be placed! :mad: Hating coding style guides and the people that are content in contriving them
"We trained hard, but it seemed that every time we were beginning to form up into teams we would be reorganised. I was to learn later in life that we tend to meet any new situation by reorganising: and a wonderful method it can be for creating the illusion of progress, while producing confusion, inefficiency and demoralisation." -- Caius Petronius, Roman Consul, 66 A.D.
jhwurmbach wrote:
Hating coding style guides and the people that are content in contriving them
Well, they should be about Standards rather than style. That's the key. I have my preferences over curly bracket placement but they wouldn't be enforced in a standards document I would write.
Kevin
