Comments on: The VAR keyword is idiotic http://www.webapper.com/blog/index.php/2007/02/05/the-var-keyword-is-idiotic/ Web Application Engineers Fri, 05 Mar 2010 10:00:57 +0000 http://wordpress.org/ hourly 1 By: Darren Cook http://www.webapper.com/blog/index.php/2007/02/05/the-var-keyword-is-idiotic/comment-page-1/#comment-425 Darren Cook Wed, 17 Oct 2007 00:00:00 +0000 http://www.webapper.net/blog/index.cfm/2007/6/29/The-VAR-keyword-is-idiotic#comment-425 I tried the test suite out and found as others have that using var was definitely the fastest. However I was curious what performance was like for the 'var local = StructNew()' and 'use the ARGUMENTS scope as a local scope' ideas. I enhanced the suite with tests for those, and found that they were quite a bit slower than using var, though still a smidge faster than using nothing. I'll be choosing to use var then, as it's no worse a discipline to develop than scoping everything. I tried the test suite out and found as others have that using var was definitely the fastest. However I was curious what performance was like for the ‘var local = StructNew()’ and ‘use the ARGUMENTS scope as a local scope’ ideas. I enhanced the suite with tests for those, and found that they were quite a bit slower than using var, though still a smidge faster than using nothing. I’ll be choosing to use var then, as it’s no worse a discipline to develop than scoping everything.

]]> By: Ben Nadel http://www.webapper.com/blog/index.php/2007/02/05/the-var-keyword-is-idiotic/comment-page-1/#comment-421 Ben Nadel Tue, 06 Feb 2007 00:00:00 +0000 http://www.webapper.net/blog/index.cfm/2007/6/29/The-VAR-keyword-is-idiotic#comment-421 I think the VAR keyword is most excellent. I like the idea of being able to define something as temporary to that function and that function only. Personally, I do what Dale Fraser does with the var LOCAL scope and that works great. I also like to scope everything. That way, I can tell the difference between LOCAL scoped variables and ARGUMENTS scope variables that might have naming conflicts. To be honest, I think the best possible solution would be to make LOCAL a build in scope for all CFFunction scopes. Basically, build in the var LOCAL = StructNew() line of code. That way, you can still explicitly set something as being local, but no need to set up the scope. Not only does this save you a step, it make your code more understandable as it self-documents the availability of a variable. If we got rid of the VAR keyword, I suspect that it would be harder to tell where keywords were supposed to be available. Although I guess if you force the scoping of non-local variable, that would also help. I think the VAR keyword is most excellent. I like the idea of being able to define something as temporary to that function and that function only. Personally, I do what Dale Fraser does with the var LOCAL scope and that works great.

I also like to scope everything. That way, I can tell the difference between LOCAL scoped variables and ARGUMENTS scope variables that might have naming conflicts.

To be honest, I think the best possible solution would be to make LOCAL a build in scope for all CFFunction scopes. Basically, build in the var LOCAL = StructNew() line of code. That way, you can still explicitly set something as being local, but no need to set up the scope.

Not only does this save you a step, it make your code more understandable as it self-documents the availability of a variable.

If we got rid of the VAR keyword, I suspect that it would be harder to tell where keywords were supposed to be available. Although I guess if you force the scoping of non-local variable, that would also help.

]]> By: Steve Nelson http://www.webapper.com/blog/index.php/2007/02/05/the-var-keyword-is-idiotic/comment-page-1/#comment-422 Steve Nelson Tue, 06 Feb 2007 00:00:00 +0000 http://www.webapper.net/blog/index.cfm/2007/6/29/The-VAR-keyword-is-idiotic#comment-422 You can also use the arguments scope as a "local" scope. As far as i can tell it's thread safe and does not need to be declared in every function. You can also use the arguments scope as a "local" scope. As far as i can tell it’s thread safe and does not need to be declared in every function.

]]> By: Ben Nadel http://www.webapper.com/blog/index.php/2007/02/05/the-var-keyword-is-idiotic/comment-page-1/#comment-423 Ben Nadel Tue, 06 Feb 2007 00:00:00 +0000 http://www.webapper.net/blog/index.cfm/2007/6/29/The-VAR-keyword-is-idiotic#comment-423 Steve, Very true, and I have done that a bunch. The only time I can ever see that being a problem is when my arguments variable A and my local variable A have different meanings (in which case the two different scopes is needed). But again, that is a special case. When I do use the ARGUMENTS scope as a local scope, I tend to feel bad, like I am cheating, or misusing it... but I get over that and realize that ARGUMENTS is neither living nor does it have feelings :) Steve,

Very true, and I have done that a bunch. The only time I can ever see that being a problem is when my arguments variable A and my local variable A have different meanings (in which case the two different scopes is needed). But again, that is a special case.

When I do use the ARGUMENTS scope as a local scope, I tend to feel bad, like I am cheating, or misusing it… but I get over that and realize that ARGUMENTS is neither living nor does it have feelings :)

]]> By: Steve Nelson http://www.webapper.com/blog/index.php/2007/02/05/the-var-keyword-is-idiotic/comment-page-1/#comment-424 Steve Nelson Tue, 06 Feb 2007 00:00:00 +0000 http://www.webapper.net/blog/index.cfm/2007/6/29/The-VAR-keyword-is-idiotic#comment-424 Yeah i agree. It does feel like cheating. There also may be an issue with this during recursion. Specifically when overwriting an arguments scoped variable. Although I'm not 100% sure about this. Yeah i agree. It does feel like cheating.

There also may be an issue with this during recursion. Specifically when overwriting an arguments scoped variable. Although I’m not 100% sure about this.

]]> By: Brian Kotek http://www.webapper.com/blog/index.php/2007/02/05/the-var-keyword-is-idiotic/comment-page-1/#comment-396 Brian Kotek Mon, 05 Feb 2007 00:00:00 +0000 http://www.webapper.net/blog/index.cfm/2007/6/29/The-VAR-keyword-is-idiotic#comment-396 I still have to admit that I don't understand what you are talking about at all, John. The only getters and setters I'm familiar with in Java or C# are those written by developers. If you want a read-only value for a CFC instance variable, you make the setter private and the getter public. This is not complicated. You can't make a variable private in the THIS scope because the THIS scope is public, just as it is in JavaScript. Still not understanding what the confusion is here. I still have to admit that I don’t understand what you are talking about at all, John. The only getters and setters I’m familiar with in Java or C# are those written by developers.

If you want a read-only value for a CFC instance variable, you make the setter private and the getter public. This is not complicated. You can’t make a variable private in the THIS scope because the THIS scope is public, just as it is in JavaScript. Still not understanding what the confusion is here.

]]> By: Nick Tong http://www.webapper.com/blog/index.php/2007/02/05/the-var-keyword-is-idiotic/comment-page-1/#comment-397 Nick Tong Mon, 05 Feb 2007 00:00:00 +0000 http://www.webapper.net/blog/index.cfm/2007/6/29/The-VAR-keyword-is-idiotic#comment-397 I agree that this is a pain at times and infact it's extra coding, but would adding this feature require extra parsing from the cf engine? Surely there must be a reason why they require us to add the 'var' manually... isn't there?? I agree that this is a pain at times and infact it’s extra coding, but would adding this feature require extra parsing from the cf engine? Surely there must be a reason why they require us to add the ‘var’ manually… isn’t there??

]]> By: Brian Kotek http://www.webapper.com/blog/index.php/2007/02/05/the-var-keyword-is-idiotic/comment-page-1/#comment-398 Brian Kotek Mon, 05 Feb 2007 00:00:00 +0000 http://www.webapper.net/blog/index.cfm/2007/6/29/The-VAR-keyword-is-idiotic#comment-398 Hey Steve, first, I've heard this might be under consideration (either automatically or as a config option) in CF8. Remember, though, that this would break anyone's code who is relying on the existing behavior. For better or worse, Adobe is very careful when breaking backward compatibility. Second, just to clarify, non-var scoped variables go into the variables scope of the containing CFC (they become instance data). So this is quite different than a "global" variable like the request scope. The two serve very different purposes. Just wanted to make sure other readers understand that! Hey Steve, first, I’ve heard this might be under consideration (either automatically or as a config option) in CF8. Remember, though, that this would break anyone’s code who is relying on the existing behavior. For better or worse, Adobe is very careful when breaking backward compatibility.

Second, just to clarify, non-var scoped variables go into the variables scope of the containing CFC (they become instance data). So this is quite different than a "global" variable like the request scope. The two serve very different purposes. Just wanted to make sure other readers understand that!

]]> By: Steve Nelson http://www.webapper.com/blog/index.php/2007/02/05/the-var-keyword-is-idiotic/comment-page-1/#comment-399 Steve Nelson Mon, 05 Feb 2007 00:00:00 +0000 http://www.webapper.net/blog/index.cfm/2007/6/29/The-VAR-keyword-is-idiotic#comment-399 Brain (I prefer that name over Brian)- Yes it would break existing code if someone is making use of turning it off (not using it). That's why I ask the question "do you ever want to NOT use it?" I'm not convinced anyone is NOT using it... on purpose. Plenty of people are not using it by accident. Like me. Whoops, I just found another one. Brain (I prefer that name over Brian)-

Yes it would break existing code if someone is making use of turning it off (not using it). That’s why I ask the question "do you ever want to NOT use it?"

I’m not convinced anyone is NOT using it… on purpose. Plenty of people are not using it by accident. Like me. Whoops, I just found another one.

]]> By: Brian Kotek http://www.webapper.com/blog/index.php/2007/02/05/the-var-keyword-is-idiotic/comment-page-1/#comment-400 Brian Kotek Mon, 05 Feb 2007 00:00:00 +0000 http://www.webapper.net/blog/index.cfm/2007/6/29/The-VAR-keyword-is-idiotic#comment-400 Basically it would probably be anyone who wrote and deployed CFC code between 6.0 and the 6.1 release. I agree that there are probably not a lot of people, and further, in this case it might be worth it for Adobe to just say "tough luck people, on this one you have to change your code". I sure wouldn't care if they did that. Basically it would probably be anyone who wrote and deployed CFC code between 6.0 and the 6.1 release. I agree that there are probably not a lot of people, and further, in this case it might be worth it for Adobe to just say "tough luck people, on this one you have to change your code". I sure wouldn’t care if they did that.

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