var
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But what if you want to reuse an object for something completely different. Can you declare var Foo2 = old FooObject; ?
"A Journey of a Thousand Rest Stops Begins with a Single Movement"
Roger Wright wrote:
var Foo2 = old FooObject;
There's no foo like an old foo. So, clearly not.
_____________________________ There is no I in team. But there is meat in there.
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varwasn't created to reduce keystrokes, and should not be used as such. Developers should strive to type more keystrokes, not fewer. -
no, the point was more to be able to have anonymous types and also in foreach and other like constructs where the type info can be combersomely unwieldy to have something more readable and understandable.
It only saves some typing, other than that it doesn't offer anything functional. I can make my own custom classes to contain my query/filter results, which will always be more readable than a non-descriptive var.
Wout
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My opinion: I'm kind of liking var. Everywhere. While I might not be able to tell the type at only a quick glance, as you say in your post, it makes the code much cleaner and elegant, IMO, as the variable declarations all stand out as a single group.
Religiously blogging on the intarwebs since the early 21st century: Kineti L'Tziyon Judah Himango
Why not just make all your own custom types 7 characters long; and build wrappers around the base classes to make them 7 characters long too?
QString bork = string.Empty
QQFloat FHeight = 12.0FReally, what I normally do is group the declarations at the top of a class inside a
#region Declarationsthen shrink it when not needed.
Ninja (the Nerd)
Confused? You will be... -
Yes.
Wout
UnstableClassInDevelopment.UnStableType.UnderlyingValue obj = new UnstableClassInDevelopment.UnStableType.UnderlyingValue();
Now, if that underlying value changes type; everything breaks. With var, you don't have to do any search/replace and it works with any reasonable change. Yes, stupid example but I don't even use the thing.
Ninja (the Nerd)
Confused? You will be... -
UnstableClassInDevelopment.UnStableType.UnderlyingValue obj = new UnstableClassInDevelopment.UnStableType.UnderlyingValue();
Now, if that underlying value changes type; everything breaks. With var, you don't have to do any search/replace and it works with any reasonable change. Yes, stupid example but I don't even use the thing.
Ninja (the Nerd)
Confused? You will be...You can just rename the type with VS refactoring couldn't you? And if some third party owns that code and changes it, I would like everything to break, so I can see what the change was exactly. Silently accepting changes is very dangerous.
Wout
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I kind of like the "new" keyword, but technically it shouldn't be needed, unless I'm missing something. Just playing devil's advocate here...
With: List<string> myList = new List<string>();
Without: List<string> myList = List<string>();The parentheses would be enough to indicate that you're calling a constructor... I do think, though, that the "new" keyword keeps things clearer. There could be issues with functions named the same as classes, but that could technically be resolved with absolute references.
Proud to have finally moved to the A-Ark. Which one are you in? Developer, Author (Guardians of Xen)
var foo = new MyFoo(); //clearly creates a new MyFoo. var foo = MyFoo(); //create a new MyFoo or call local method MyFoo()? var foo = MyFoo; //create a new MyFoo or assign local field MyFoo?
Truth, James
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Roger Wright wrote:
var Foo2 = old FooObject;
There's no foo like an old foo. So, clearly not.
_____________________________ There is no I in team. But there is meat in there.
I pity the foo! - Mr <T>
"The activity of 'debugging', or removing bugs from a program, ends when people get tired of doing it, not when the bugs are removed." - "Datamation", January 15, 1984
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Marc Clifton wrote:
var foo = factory.CreateAFoo()
Meh, in your example
foois eitherFooorIFoo. On a slightly related note: why on earth C# (or Java) need keywordnewin the first place? It is completely redundant.>> why on earth C# (or Java) need keyword new in the first place? It is completely redundant. It's not for the compiler, but for human readers. The goal was that the programmer's intend is always clear. For more examples, there's no reason why classes need to be marked abstract; or that virtual methods be marked "new" or "override"; or that we have both "ref" and "out" to mark parameters. none of those affects the generated IL at all.
Truth, James
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It still bugs me that you can't write "new List" in C#, you have to write "new List()" But maybe I'm just a crusty old C++ guy. ;P
--Mike-- Dunder-Mifflin, this is Pam
I write
new List()even in C++. The constructor is a function, even if it's implicit.If you can play The Dance of Eternity (Dream Theater), then we shall make a band.
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I pity the foo! - Mr <T>
"The activity of 'debugging', or removing bugs from a program, ends when people get tired of doing it, not when the bugs are removed." - "Datamation", January 15, 1984
I pity the foo! Now eat my cereal - Pee Wee Herman acting like Mr
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Why not just make all your own custom types 7 characters long; and build wrappers around the base classes to make them 7 characters long too?
QString bork = string.Empty
QQFloat FHeight = 12.0FReally, what I normally do is group the declarations at the top of a class inside a
#region Declarationsthen shrink it when not needed.
Ninja (the Nerd)
Confused? You will be...Ninja-the-Nerd wrote:
Why not just make all your own custom types 7 characters long;
Length isn't the issue.
Ninja-the-Nerd wrote:
Really, what I normally do is group the declarations at the top of a class inside a #region Declarations then shrink it when not needed.
Me too. But var doesn't work for fields in a class. Only works for locals.
Religiously blogging on the intarwebs since the early 21st century: Kineti L'Tziyon Judah Himango
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So, there's been a lot of posts about whether var (C# thingy, for those non-C# folks) is good, bad, or just ugly. Well, I can deal with:
var foo = new List();as an example, because it's obvious what foo is. What I really hate is something like this:var foo = factory.CreateAFoo()That's where I despise seeing a "var"! MarcI'm not overthinking the problem, I just felt like I needed a small, unimportant, uninteresting rant! - Martin Hart Turner
There is another side to this. That the example you gave of var foo = factory.CreateAFoo() and lets assume that CreateAFoo returns a IFoo interface. Now assume that at some point you add a new method to the interface can create a IFoo2 interface. You don't have to change your code. I like var ... less typing and if I can't easily figure out the type, then that tells me that the code needs a comment :-)
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So, there's been a lot of posts about whether var (C# thingy, for those non-C# folks) is good, bad, or just ugly. Well, I can deal with:
var foo = new List();as an example, because it's obvious what foo is. What I really hate is something like this:var foo = factory.CreateAFoo()That's where I despise seeing a "var"! MarcI'm not overthinking the problem, I just felt like I needed a small, unimportant, uninteresting rant! - Martin Hart Turner
Perhaps I'm daft, but you do need to indicate a consturctor - so as to call the default constructor and possibly others (with parameters or different name). However I do agree that var foo = some-type could cause default constructor invokation/object creation while the second example from the factory would work without new because you're in theory returning a pointer to an instanced object. Ultimately New does seem redundant to me, but you still need a clear semantic/syntax to be able to indicate default and potentially other constructor invocation for class/object creation --Jason
Know way too many languages... master of none!
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>> why on earth C# (or Java) need keyword new in the first place? It is completely redundant. It's not for the compiler, but for human readers. The goal was that the programmer's intend is always clear. For more examples, there's no reason why classes need to be marked abstract; or that virtual methods be marked "new" or "override"; or that we have both "ref" and "out" to mark parameters. none of those affects the generated IL at all.
Truth, James
Keywords like
abstractnot only show the intent, but enforce it as well.James Curran wrote:
none of those affects the generated IL at all
Then how are they enforced when you refer to something in an assembly?
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You can just rename the type with VS refactoring couldn't you? And if some third party owns that code and changes it, I would like everything to break, so I can see what the change was exactly. Silently accepting changes is very dangerous.
Wout
Hear hear!
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Marc Clifton wrote:
var foo = factory.CreateAFoo()
Meh, in your example
foois eitherFooorIFoo. On a slightly related note: why on earth C# (or Java) need keywordnewin the first place? It is completely redundant.Nemanja Trifunovic wrote:
why on earth C# (or Java) need keyword new in the first place? It is completely redundant
Hey Nemanja I've been thinking that very thought ever since Java and then C# came along but I'd never voiced it before! :)
Kevin
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So, there's been a lot of posts about whether var (C# thingy, for those non-C# folks) is good, bad, or just ugly. Well, I can deal with:
var foo = new List();as an example, because it's obvious what foo is. What I really hate is something like this:var foo = factory.CreateAFoo()That's where I despise seeing a "var"! MarcI'm not overthinking the problem, I just felt like I needed a small, unimportant, uninteresting rant! - Martin Hart Turner
Not really used var in anger. But the first will probably be my usage pattern going forward.
Kevin
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Nemanja Trifunovic wrote:
Meh, in your example foo is either Foo or IFoo.
Agreed. The example was bad, but you know what I meant. :)
Nemanja Trifunovic wrote:
why on earth C# (or Java) need keyword new in the first place? It is completely redundant.
Because it gives everyone a warm fuzzy feeling that something important is happening. Just be glad we don't have to use the "Let" keyword (though, in some functional languages, it's baaaaack!) Marc
I'm not overthinking the problem, I just felt like I needed a small, unimportant, uninteresting rant! - Martin Hart Turner
Marc Clifton wrote:
Just be glad we don't have to use the "Let" keyword (though, in some functional languages, it's baaaaack!)
e.g., in F#. Let is just var (well, actually it's val if you compare it to Scala which has var and val - var for mutables, val for immutables).
Kevin
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Marc Clifton wrote:
var foo = factory.CreateAFoo()
Meh, in your example
foois eitherFooorIFoo. On a slightly related note: why on earth C# (or Java) need keywordnewin the first place? It is completely redundant.Why is there a "new"? This is to keep Java and C# more in line with C++, and to help woo over more C++ programmers. It does, generally, the same thing as in C++, therefore something that the C++ programmers need not learn. Yes, us old C++ programmers need something familiar to help win our hearts. But, you don't need to delete what you new'ed. That gets gc'd.