c# var
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The advantage of var is if
"http://someapi"was a variable or class instance instead of a string literal and you changed its type, you would not then need to refactor the code elsewhere. In your example it's just a case of habit probably, however it's obvious from what is on the right that it's a string. It can sometimes make it harder to debug issues as jumping to the class definition might not always be supported in the IDE you use to debug thevar urlvalue with or have to wait for the IDE to resolve the type that thevaris. That's my take onvar...“That which can be asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
GuyThiebaut wrote:
The advantage of var is if
"http://someapi"was a variable or class instance instead of a string literal and you changed its type, you would not then need to refactor the code elsewhere.Absolutely not true. Changing a data type and then attempting to use it elsewhere is guaranteed to cause you to have to modify code everywhere it's used. Fortunately the VS IDE is smart enough to identify those spots for you.
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I'd actually prefer it is you could do this:
Dictionary> complicatedDictionary = new *();
To me, that would be a more natural way of showing what the type of
complicatedDictionaryactually is. As it is, I findvaris mainly over used by the lazy-and-don't-care script kiddies ..."I have no idea what I did, but I'm taking full credit for it." - ThisOldTony AntiTwitter: @DalekDave is now a follower!
This is one place where VB has a better syntax:
dim complicatedDictionary as New Dictionary(of SomeKey, List(KeyValue))
I'd prefer to see the < and > symbols used around the type information as this would make it clear what is type information vs. New parameters/arguments.
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GuyThiebaut wrote:
The advantage of var is if
"http://someapi"was a variable or class instance instead of a string literal and you changed its type, you would not then need to refactor the code elsewhere.Absolutely not true. Changing a data type and then attempting to use it elsewhere is guaranteed to cause you to have to modify code everywhere it's used. Fortunately the VS IDE is smart enough to identify those spots for you.
obermd wrote:
Absolutely not true. Changing a data type and then attempting to use it elsewhere is guaranteed to cause you to have to modify code everywhere it's used.
Even when changing from a
shortto along?“That which can be asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
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What is the love affair with var? I see sample code where they do something like
var url = "http://someapi";
This feels lazy to me but I am open minded and am curious if I am missing something. Is there some benefit to declaring most things var instead of what they actually are? In the case above, a string.
Social Media - A platform that makes it easier for the crazies to find each other. Everyone is born right handed. Only the strongest overcome it. Fight for left-handed rights and hand equality.
I rarely use var but I do use it when returning a tuple from a method to avoid
outparameters. For examplevoid MainMethod() {
...
var methodCall = SomeMethod();
if (!methodCall.Success) {
return;
}
...
}(bool Success, int? ReturnValue) SomeMethod() {
int? retValue;...
if (...) {
return (Success: false, ReturnValue: null);
}
...return (Success: true, ReturnValue: retValue):
} -
I'd actually prefer it is you could do this:
Dictionary> complicatedDictionary = new *();
To me, that would be a more natural way of showing what the type of
complicatedDictionaryactually is. As it is, I findvaris mainly over used by the lazy-and-don't-care script kiddies ..."I have no idea what I did, but I'm taking full credit for it." - ThisOldTony AntiTwitter: @DalekDave is now a follower!
That should hopefully be coming in C# 9: csharplang/target-typed-new.md at master · dotnet/csharplang · GitHub[^] Champion "Target-typed `new` expression" · Issue #100 · dotnet/csharplang · GitHub[^] Edit: As already mentioned in the Insider News[^]. :)
"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer
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I rarely use var but I do use it when returning a tuple from a method to avoid
outparameters. For examplevoid MainMethod() {
...
var methodCall = SomeMethod();
if (!methodCall.Success) {
return;
}
...
}(bool Success, int? ReturnValue) SomeMethod() {
int? retValue;...
if (...) {
return (Success: false, ReturnValue: null);
}
...return (Success: true, ReturnValue: retValue):
}Or better yet:
var (Success, ReturnValue) = SomeMethod();
if (!Success) {
return;
}
"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer
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That should hopefully be coming in C# 9: csharplang/target-typed-new.md at master · dotnet/csharplang · GitHub[^] Champion "Target-typed `new` expression" · Issue #100 · dotnet/csharplang · GitHub[^] Edit: As already mentioned in the Insider News[^]. :)
"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer
Hah! I just spent half an hour trying to persuade Google to let me know how you make suggestions for the C# spec ... :laugh: That language change I will use!
"I have no idea what I did, but I'm taking full credit for it." - ThisOldTony AntiTwitter: @DalekDave is now a follower!
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What is the love affair with var? I see sample code where they do something like
var url = "http://someapi";
This feels lazy to me but I am open minded and am curious if I am missing something. Is there some benefit to declaring most things var instead of what they actually are? In the case above, a string.
Social Media - A platform that makes it easier for the crazies to find each other. Everyone is born right handed. Only the strongest overcome it. Fight for left-handed rights and hand equality.
Ah, the use of var. I know that some people use var to do code alignment on variable names; the idea being that it's easier to scan the name if it lines up.
private void DoSomething()
{
var apiEndpoint = new Uri("http://someapi");
var retryCount = 10;
var longClassName = new ThisIsAReallyLongNameThatWouldReallyScrewUpTheClassNameDeclaration();
// body of the method.
} -
The only benefit is that if you don't understand types then there is a chance your code will work using var even though you don't know why. Also I've found some common style tools dictate you should use var. I don't mind it for
var name = "Blah";
or
var people = new List();
but I hate it when people use it for things like
var data = SomeFunction();
In C++
auto i = small integer // seems rather silly, and obscures signed/unsigned
auto v = some complex STL type // is handy
auto l = some big elephanting lambda // is required, and why they added it"If we don't change direction, we'll end up where we're going"
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I'd actually prefer it is you could do this:
Dictionary> complicatedDictionary = new *();
To me, that would be a more natural way of showing what the type of
complicatedDictionaryactually is. As it is, I findvaris mainly over used by the lazy-and-don't-care script kiddies ..."I have no idea what I did, but I'm taking full credit for it." - ThisOldTony AntiTwitter: @DalekDave is now a follower!
I kind of find it easier to read with var first. But this is more secure, since you have to know what you are going to need and the you create the new instance in the lazy mode. Best of both options, I guess
M.D.V. ;) If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about? Help me to understand what I'm saying, and I'll explain it better to you Rating helpful answers is nice, but saying thanks can be even nicer.
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I'd actually prefer it is you could do this:
Dictionary> complicatedDictionary = new *();
To me, that would be a more natural way of showing what the type of
complicatedDictionaryactually is. As it is, I findvaris mainly over used by the lazy-and-don't-care script kiddies ..."I have no idea what I did, but I'm taking full credit for it." - ThisOldTony AntiTwitter: @DalekDave is now a follower!
OriginalGriff wrote:
that would be a more natural way of showing what the type
Yup. And as I replied on the Insider News, what I really want is:
var foo = new();In most cases, the compiler should be able to figure out whatfoois by inspecting its usage in the code! :laugh:Latest Articles:
Abusing Extension Methods, Null Continuation, and Null Coalescence Operators -
Ah, the use of var. I know that some people use var to do code alignment on variable names; the idea being that it's easier to scan the name if it lines up.
private void DoSomething()
{
var apiEndpoint = new Uri("http://someapi");
var retryCount = 10;
var longClassName = new ThisIsAReallyLongNameThatWouldReallyScrewUpTheClassNameDeclaration();
// body of the method.
}Pete O'Hanlon wrote:
the idea being that it's easier to scan the name if it lines up.
:thumbsup::thumbsup: That's my main argument (readability) and why I like it. On the other hand, incoming Option #3[^] is good too. It is a bit less readable, but still "forces" you to by type strong but combined with the lazyness / don't break the lines with long names too.
M.D.V. ;) If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about? Help me to understand what I'm saying, and I'll explain it better to you Rating helpful answers is nice, but saying thanks can be even nicer.
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What is the love affair with var? I see sample code where they do something like
var url = "http://someapi";
This feels lazy to me but I am open minded and am curious if I am missing something. Is there some benefit to declaring most things var instead of what they actually are? In the case above, a string.
Social Media - A platform that makes it easier for the crazies to find each other. Everyone is born right handed. Only the strongest overcome it. Fight for left-handed rights and hand equality.
is it lazy. Sure is. Does it work. Unfortunately yes and Fortunately yes. AS mentioned already when refactoring code and say a variable changes from int to long or even to a string it makes sure the code continues to work. I don't like it. but that does not mean I have never used it. I have and I hate myself for it. But I remember one time I had to write a bit of code. The co-workers insisted that the variable would always be an integer. ALWAYS they said. having some experience I knew probably gonna change. About a year later system requirements changed. I had used var and the code still worked. sooooooo tldr; lazy yes, flexible yes, hate myself yes.
To err is human to really mess up you need a computer
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it is good for a lot of applications but can be missused very easily. it's main purpose is code readability.
MyMostExcellentBaseClassOfAllClassesInTheWholeWorld myClass = new MyMostExcellentBaseClassOfAllClassesInTheWholeWorld();
or
var myClass = new MyMostExcellentBaseClassOfAllClassesInTheWholeWorld();
It is really good when working with Linq, etc. as well.
Slacker007 wrote:
it's main purpose is code readability.
Its main purpose is actually anonymous types.
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Slacker007 wrote:
it's main purpose is code readability.
Its main purpose is actually anonymous types.
I guess it could be used for both, but most people use it for implicit, which by nature adds to code readability for most. Edit: implicit and anonymous. but when I use it, I am not thinking "anonymous" or "Implicit" etc, I am thinking code readability. var - C# Reference | Microsoft Docs[^] c# - Implicitly Typed vs Anonymous Type - Stack Overflow[^]
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is it lazy. Sure is. Does it work. Unfortunately yes and Fortunately yes. AS mentioned already when refactoring code and say a variable changes from int to long or even to a string it makes sure the code continues to work. I don't like it. but that does not mean I have never used it. I have and I hate myself for it. But I remember one time I had to write a bit of code. The co-workers insisted that the variable would always be an integer. ALWAYS they said. having some experience I knew probably gonna change. About a year later system requirements changed. I had used var and the code still worked. sooooooo tldr; lazy yes, flexible yes, hate myself yes.
To err is human to really mess up you need a computer
The problem with that is that you are working to what should have been a breaking change. And that's important, because if you were assuming int division as a result of the original type spec for example, then a breaking change means you know it's just failed and can adapt to it.
varin that case means you don't know, and output can be subtly wrong and unnoticed until it's a real problem. I'd say var should be there for temporary storage of Linq results, and nowhere else ..."I have no idea what I did, but I'm taking full credit for it." - ThisOldTony AntiTwitter: @DalekDave is now a follower!
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What is the love affair with var? I see sample code where they do something like
var url = "http://someapi";
This feels lazy to me but I am open minded and am curious if I am missing something. Is there some benefit to declaring most things var instead of what they actually are? In the case above, a string.
Social Media - A platform that makes it easier for the crazies to find each other. Everyone is born right handed. Only the strongest overcome it. Fight for left-handed rights and hand equality.
That's just pure laziness.
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ZurdoDev wrote:
This feels lazy to me but I am open minded and am curious if I am missing something. Is there some benefit to declaring most things var instead of what they actually are? In the case above, a string.
I felt the same way initially, and I agree, for something simple like a native type, I rarely use var. However:
var complicatedDictionary = new Dictionary>();and worse, I like definitely like it.Latest Articles:
Abusing Extension Methods, Null Continuation, and Null Coalescence Operators+1 For native types, I don't see the point in using var. I also subscribe to the idea of using: var x = new SomeMoreComplexType(); I don't mind: var x = SomeFunction(); ...if *I* don't particularly case about the type returned, for example, if I only use it to forward to some other function and I'm not looking at any of its members myself.
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What is the love affair with var? I see sample code where they do something like
var url = "http://someapi";
This feels lazy to me but I am open minded and am curious if I am missing something. Is there some benefit to declaring most things var instead of what they actually are? In the case above, a string.
Social Media - A platform that makes it easier for the crazies to find each other. Everyone is born right handed. Only the strongest overcome it. Fight for left-handed rights and hand equality.
ZurdoDev wrote:
var url = "http://someapi";
Is there some benefit to declaring most things var instead of what they actually are? In the case above, a string.
Is it a string? Could it be a URI[^]
Uri siteUri = new Uri("http://www.contoso.com/");
Director of Transmogrification Services Shinobi of Query Language Master of Yoda Conditional
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ZurdoDev wrote:
var url = "http://someapi";
Is there some benefit to declaring most things var instead of what they actually are? In the case above, a string.
Is it a string? Could it be a URI[^]
Uri siteUri = new Uri("http://www.contoso.com/");
Director of Transmogrification Services Shinobi of Query Language Master of Yoda Conditional
