Code Neatness
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So somewhere on the internet, I pointed out to a newbie that his code was pretty messy and that he should start by consolidating some of his variable declarations to the beginning of the program (which was consisted of only a main(…) function/method/entry point and a lot of improperly formatted code). In walks another forum member and criticizes me for my comment saying that "it's a feature of the C++ language to be able to declare variables anywhere you need it." I was obviously pissed at that comment showing his utter disregard for code neatness and readability (and likely a malicious attack on my intelligence). I'm trying to seek agreement… so was I right when I said so?
So the creationist says: Everything must have a designer. God designed everything. I say: Why is God the only exception? Why not make the "designs" (like man) exceptions and make God a creation of man?
I disagree with you - declare as you need them
Christian Graus - Microsoft MVP - C++ "also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )
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So somewhere on the internet, I pointed out to a newbie that his code was pretty messy and that he should start by consolidating some of his variable declarations to the beginning of the program (which was consisted of only a main(…) function/method/entry point and a lot of improperly formatted code). In walks another forum member and criticizes me for my comment saying that "it's a feature of the C++ language to be able to declare variables anywhere you need it." I was obviously pissed at that comment showing his utter disregard for code neatness and readability (and likely a malicious attack on my intelligence). I'm trying to seek agreement… so was I right when I said so?
So the creationist says: Everything must have a designer. God designed everything. I say: Why is God the only exception? Why not make the "designs" (like man) exceptions and make God a creation of man?
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So somewhere on the internet, I pointed out to a newbie that his code was pretty messy and that he should start by consolidating some of his variable declarations to the beginning of the program (which was consisted of only a main(…) function/method/entry point and a lot of improperly formatted code). In walks another forum member and criticizes me for my comment saying that "it's a feature of the C++ language to be able to declare variables anywhere you need it." I was obviously pissed at that comment showing his utter disregard for code neatness and readability (and likely a malicious attack on my intelligence). I'm trying to seek agreement… so was I right when I said so?
So the creationist says: Everything must have a designer. God designed everything. I say: Why is God the only exception? Why not make the "designs" (like man) exceptions and make God a creation of man?
Matter of preference, really, as long as you don't declare inside a loop... but, yeah, I generally put them at the top if the method is not long. Otherwise, I group them in blocks near where they are used...
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So somewhere on the internet, I pointed out to a newbie that his code was pretty messy and that he should start by consolidating some of his variable declarations to the beginning of the program (which was consisted of only a main(…) function/method/entry point and a lot of improperly formatted code). In walks another forum member and criticizes me for my comment saying that "it's a feature of the C++ language to be able to declare variables anywhere you need it." I was obviously pissed at that comment showing his utter disregard for code neatness and readability (and likely a malicious attack on my intelligence). I'm trying to seek agreement… so was I right when I said so?
So the creationist says: Everything must have a designer. God designed everything. I say: Why is God the only exception? Why not make the "designs" (like man) exceptions and make God a creation of man?
Ri Qen-Sin wrote:
so was I right when I said so?
No. C required you to declare variables at the beginning of a function, because C (and C++) allocate all local variables when the stack frame is being constructed, and it simplified the compiler. C++ doesn't require this. Making me scan back through your code looking for a variable declaration isn't being neat. It's just being rude. I actually had to explain this to a new consultant last week, when he tried to argue that throwing a dozen variable declarations at the top of a rather large function increased efficiency by avoiding allocations in a loop. Good grief. Do people not know how to generate assembler output from their compilers anymore? :suss:
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Ri Qen-Sin wrote:
so was I right when I said so?
No. C required you to declare variables at the beginning of a function, because C (and C++) allocate all local variables when the stack frame is being constructed, and it simplified the compiler. C++ doesn't require this. Making me scan back through your code looking for a variable declaration isn't being neat. It's just being rude. I actually had to explain this to a new consultant last week, when he tried to argue that throwing a dozen variable declarations at the top of a rather large function increased efficiency by avoiding allocations in a loop. Good grief. Do people not know how to generate assembler output from their compilers anymore? :suss:
Shog9 wrote:
Do people not know how to generate assembler output from their compilers anymore?
Nope. And if they did can they read it?
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects. - -Lazarus Long
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Shog9 wrote:
Do people not know how to generate assembler output from their compilers anymore?
Nope. And if they did can they read it?
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects. - -Lazarus Long
:laugh: There's a reason why, after an hour spent carefully formatting the diff of the compiler-generated assembler for in-loop and function start variables, i scrapped it and just declared that it was identical. Some arguments just aren't worth the time... :sigh:
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So somewhere on the internet, I pointed out to a newbie that his code was pretty messy and that he should start by consolidating some of his variable declarations to the beginning of the program (which was consisted of only a main(…) function/method/entry point and a lot of improperly formatted code). In walks another forum member and criticizes me for my comment saying that "it's a feature of the C++ language to be able to declare variables anywhere you need it." I was obviously pissed at that comment showing his utter disregard for code neatness and readability (and likely a malicious attack on my intelligence). I'm trying to seek agreement… so was I right when I said so?
So the creationist says: Everything must have a designer. God designed everything. I say: Why is God the only exception? Why not make the "designs" (like man) exceptions and make God a creation of man?
In addition to the other replies... Besides readability, there's also variable scope in C++. Everything at the top means method-wide scope - that's not always desired! Mark
Mark Salsbery Microsoft MVP - Visual C++ :java:
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In addition to the other replies... Besides readability, there's also variable scope in C++. Everything at the top means method-wide scope - that's not always desired! Mark
Mark Salsbery Microsoft MVP - Visual C++ :java:
Yes, I'm aware of that: my style is to declare it as close to the beginning as possible while keeping all the local variables deifnitions in the most local scope. I like to keep definitions in one spot so I know what variables I have.
So the creationist says: Everything must have a designer. God designed everything. I say: Why is God the only exception? Why not make the "designs" (like man) exceptions and make God a creation of man?
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Matter of preference, really, as long as you don't declare inside a loop... but, yeah, I generally put them at the top if the method is not long. Otherwise, I group them in blocks near where they are used...
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Yes, I'm aware of that: my style is to declare it as close to the beginning as possible while keeping all the local variables deifnitions in the most local scope. I like to keep definitions in one spot so I know what variables I have.
So the creationist says: Everything must have a designer. God designed everything. I say: Why is God the only exception? Why not make the "designs" (like man) exceptions and make God a creation of man?
Ri Qen-Sin wrote:
I like to keep definitions in one spot so I know what variables I have.
Why? Whilst much of this is 'in the eye of the beholder' and so there is no right answer, if the objective is clear and understandable code, what advantange is there in separating the declaration of a variable from its first use? Additionally, in C++, for classes with a constructor, the declaration is a function call and so the location of this call is often determined otherwise, e.g.
CString fname; // work out and assign something to fname ofstream out(fname); // do something with outI can't see how reorganising the code to declare 'out' at the beginning 'so that you know what variables you have' in any way would improve the code.Peter "Until the invention of the computer, the machine gun was the device that enabled humans to make the most mistakes in the smallest amount of time."
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So somewhere on the internet, I pointed out to a newbie that his code was pretty messy and that he should start by consolidating some of his variable declarations to the beginning of the program (which was consisted of only a main(…) function/method/entry point and a lot of improperly formatted code). In walks another forum member and criticizes me for my comment saying that "it's a feature of the C++ language to be able to declare variables anywhere you need it." I was obviously pissed at that comment showing his utter disregard for code neatness and readability (and likely a malicious attack on my intelligence). I'm trying to seek agreement… so was I right when I said so?
So the creationist says: Everything must have a designer. God designed everything. I say: Why is God the only exception? Why not make the "designs" (like man) exceptions and make God a creation of man?
Also, in addition to above comments, declaring variables at the top could stem from variable name re-use in C, C++: So at the top of a function you'd have: int i, j; Then you could re-use those variables in your function multiple times and the memory would only be allocated once. for (i = 0; i < blah, i++) { for (j = 0; j < blahblah; j++) do something; } for (i = 0; i < blah, i++) { for (j = 0; j < blahblah; j++) do something else; } In todays languages it would be: for (int i = 0; i < blah, i++) { for (int j = 0; j < blahblah; j++) do something; } for (int i = 0; i < blah, i++) { for (int j = 0; j < blahblah; j++) do something else; } ... but if you try that in C++ you get a duplicate definition error on i. Just trying to justify declaring variables at the top, I don't think there's a right or wrong way. Personally, I declare them as close to the point of use, as other people have mentioned, but if they're generic, reusable index variables I do them at the top. Then again, I'm old school. Compilers optimize this stuff for us now, but it's a hard habit to break. In my head, defining int j inside another loop will cause a memory allocation each time through the first loop. Ramblin' on....
- S 50 cups of coffee and you know it's on!
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Yes, I'm aware of that: my style is to declare it as close to the beginning as possible while keeping all the local variables deifnitions in the most local scope. I like to keep definitions in one spot so I know what variables I have.
So the creationist says: Everything must have a designer. God designed everything. I say: Why is God the only exception? Why not make the "designs" (like man) exceptions and make God a creation of man?
You're still talking readability.... I'm referring to taking advantage of the scoping of variables within functions in C++. Besides that, to me, it's more readable to me if the declarations are close by. Mark
Mark Salsbery Microsoft MVP - Visual C++ :java:
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Ravi Bhavnani wrote:
as long as you don't declare inside a loop Why not?
Because every time around the loop the stack will be adjusted for the "new" variable, and then re-adjusted as the variable goes "out of scope". Try it a million times or so and see what happens. Seriously, most compilers will hoist the variable declaration out of the loop scope, but do you want to take the risk that the particular compiler that you're using will? Apropos the OP's question. You started programming in C, didn't you... Do you still use Hungarian notation? Some times it's better to just let go. ;-) You could try using more blocks if you absolutely must have declarations at the opening paren. Cheers, P.
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Ravi Bhavnani wrote:
as long as you don't declare inside a loop Why not?
Because every time around the loop the stack will be adjusted for the "new" variable, and then re-adjusted as the variable goes "out of scope". Try it a million times or so and see what happens. Seriously, most compilers will hoist the variable declaration out of the loop scope, but do you want to take the risk that the particular compiler that you're using will? Apropos the OP's question. You started programming in C, didn't you... Do you still use Hungarian notation? Some times it's better to just let go. ;-) You could try using more blocks if you absolutely must have declarations at the opening paren. Cheers, P.
AmazingMo wrote:
Try it a million times or so and see what happens.
If the code loops a million times, I think we have a much bigger problem. :)
AmazingMo wrote:
most compilers will hoist the variable declaration out of the loop scope, but do you want to take the risk that the particular compiler that you're using will?
[edit] I can't imagine I'd use one that didn't do that as part of standard optimization! Code hoisting has been around for decades and is pretty mature technology. [/edit]
AmazingMo wrote:
You started programming in C, didn't you
No. I started programming before the first mainstream C compilers came to market. /ravi
My new year resolution: 2048 x 1536 Home | Music | Articles | Freeware ravib(at)ravib(dot)com
modified on Monday, March 10, 2008 2:17 AM
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Also, in addition to above comments, declaring variables at the top could stem from variable name re-use in C, C++: So at the top of a function you'd have: int i, j; Then you could re-use those variables in your function multiple times and the memory would only be allocated once. for (i = 0; i < blah, i++) { for (j = 0; j < blahblah; j++) do something; } for (i = 0; i < blah, i++) { for (j = 0; j < blahblah; j++) do something else; } In todays languages it would be: for (int i = 0; i < blah, i++) { for (int j = 0; j < blahblah; j++) do something; } for (int i = 0; i < blah, i++) { for (int j = 0; j < blahblah; j++) do something else; } ... but if you try that in C++ you get a duplicate definition error on i. Just trying to justify declaring variables at the top, I don't think there's a right or wrong way. Personally, I declare them as close to the point of use, as other people have mentioned, but if they're generic, reusable index variables I do them at the top. Then again, I'm old school. Compilers optimize this stuff for us now, but it's a hard habit to break. In my head, defining int j inside another loop will cause a memory allocation each time through the first loop. Ramblin' on....
- S 50 cups of coffee and you know it's on!
Steve Echols wrote:
n todays languages it would be: for (int i = 0; i < blah, i++) { for (int j = 0; j < blahblah; j++) do something; } for (int i = 0; i < blah, i++) { for (int j = 0; j < blahblah; j++) do something else; } ... but if you try that in C++ you get a duplicate definition error on i.
I was under the impression that this is an error in your compiler. If you're using Visual Studio, go to the Project Property Pages, C/C++ -> Language -> Force Conformance in For Loop Scope, and select "Yes". That ought to fix your problem. Cheers, P.
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Steve Echols wrote:
n todays languages it would be: for (int i = 0; i < blah, i++) { for (int j = 0; j < blahblah; j++) do something; } for (int i = 0; i < blah, i++) { for (int j = 0; j < blahblah; j++) do something else; } ... but if you try that in C++ you get a duplicate definition error on i.
I was under the impression that this is an error in your compiler. If you're using Visual Studio, go to the Project Property Pages, C/C++ -> Language -> Force Conformance in For Loop Scope, and select "Yes". That ought to fix your problem. Cheers, P.
Yeah, you're right, I was thinking in C#/VB. :)
- S 50 cups of coffee and you know it's on!
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Ravi Bhavnani wrote:
as long as you don't declare inside a loop Why not?
Because every time around the loop the stack will be adjusted for the "new" variable, and then re-adjusted as the variable goes "out of scope". Try it a million times or so and see what happens. Seriously, most compilers will hoist the variable declaration out of the loop scope, but do you want to take the risk that the particular compiler that you're using will? Apropos the OP's question. You started programming in C, didn't you... Do you still use Hungarian notation? Some times it's better to just let go. ;-) You could try using more blocks if you absolutely must have declarations at the opening paren. Cheers, P.
AmazingMo wrote:
Do you still use Hungarian notation? Some times it's better to just let go.
The original concept of Hungarian Notation was actually quite different from M$s butchery of it. I forget the actual words used to define the concept but the prefix was really meant to indicate the usage of the variable, not its data-type. E.g.
//M$: DWORD dwVar1, dwVar2; // M$ uses prefix to denote type // not very useful in the grand scheme of things, // since the compiler picks up type mismatches // What is the variable used for? // You have to scan the code to find out for (dwVar1 = 0UL; dwVar1 ... { for (dwVar2 = 0UL; dwVar2 ... //Original Hungarian: DWORD outerIterVar, innerIterVar; // Original Hungarian uses prefix to denote usage (e.g. "outer iterator"), // giving the programmer an idea of the intended usage of the variable // without having to scan the code for (outerIterVar = 0UL; outerIterVar ... { for (innerIterVar = 0UL; innerIterVar ...Having worked with MFC and WinAPI for so many years, it came as a surprise to learn this but I saw the sense in it right away & have tried to "do it properly" ever since. Unfortunately, old habits die hard... sigh.T-Mac-Oz
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AmazingMo wrote:
Try it a million times or so and see what happens.
If the code loops a million times, I think we have a much bigger problem. :)
AmazingMo wrote:
most compilers will hoist the variable declaration out of the loop scope, but do you want to take the risk that the particular compiler that you're using will?
[edit] I can't imagine I'd use one that didn't do that as part of standard optimization! Code hoisting has been around for decades and is pretty mature technology. [/edit]
AmazingMo wrote:
You started programming in C, didn't you
No. I started programming before the first mainstream C compilers came to market. /ravi
My new year resolution: 2048 x 1536 Home | Music | Articles | Freeware ravib(at)ravib(dot)com
modified on Monday, March 10, 2008 2:17 AM
Ravi Bhavnani wrote:
If the code loops a million times, I think we have a much bigger problem.
Like tons of legacy data stored in a stupid system....I could go on but I'd be moved to the soapbox.
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects. - -Lazarus Long
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AmazingMo wrote:
Try it a million times or so and see what happens.
If the code loops a million times, I think we have a much bigger problem. :)
AmazingMo wrote:
most compilers will hoist the variable declaration out of the loop scope, but do you want to take the risk that the particular compiler that you're using will?
[edit] I can't imagine I'd use one that didn't do that as part of standard optimization! Code hoisting has been around for decades and is pretty mature technology. [/edit]
AmazingMo wrote:
You started programming in C, didn't you
No. I started programming before the first mainstream C compilers came to market. /ravi
My new year resolution: 2048 x 1536 Home | Music | Articles | Freeware ravib(at)ravib(dot)com
modified on Monday, March 10, 2008 2:17 AM
Ravi Bhavnani wrote:
If the code loops a million times, I think we have a much bigger problem.
Usually the problem that requires millions of iterations in it's solution :-D Search engine query? How many hash buckets would you need to eliminate child node searches altogether? "grep"ing a large text (or set of) files. SQL query on a large database (somebody's got to write the query engine!) Sure, these are examples of stuff that typically has a multitude of pre-existing, mature solutions but a) they're just examples to show that there are domains where millions of iterations can be reasonably expected b) Somebody's got to maintain it!
T-Mac-Oz
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AmazingMo wrote:
Do you still use Hungarian notation? Some times it's better to just let go.
The original concept of Hungarian Notation was actually quite different from M$s butchery of it. I forget the actual words used to define the concept but the prefix was really meant to indicate the usage of the variable, not its data-type. E.g.
//M$: DWORD dwVar1, dwVar2; // M$ uses prefix to denote type // not very useful in the grand scheme of things, // since the compiler picks up type mismatches // What is the variable used for? // You have to scan the code to find out for (dwVar1 = 0UL; dwVar1 ... { for (dwVar2 = 0UL; dwVar2 ... //Original Hungarian: DWORD outerIterVar, innerIterVar; // Original Hungarian uses prefix to denote usage (e.g. "outer iterator"), // giving the programmer an idea of the intended usage of the variable // without having to scan the code for (outerIterVar = 0UL; outerIterVar ... { for (innerIterVar = 0UL; innerIterVar ...Having worked with MFC and WinAPI for so many years, it came as a surprise to learn this but I saw the sense in it right away & have tried to "do it properly" ever since. Unfortunately, old habits die hard... sigh.T-Mac-Oz
