string versus String !

_Q12_

string versus String ! I have a question (a little embarrassing because I see it so late), what is the difference between String and string ? not in the way that String is a Class and string is a reference type. But rather how to think about them in the term of uses. I searched and find this piece of gold, but I don't know how to use it very well: Use "String" to refer specifically to the String class. Use "string" when referring to an object of the String class. How to use them, accordingly? thanks again.

0x3c0

String == string. They're aliases of the same class, just like ulong is an alias of UInt64

Between the idea And the reality Between the motion And the act Falls the Shadow

Saksida Bojan

They are the same. If you want to use reference try like this:

String someString = "";
DoSomething(ref someString);

// Now someString has new value

Function:
private void DoSomething(ref String str)
{
str = "Was Empty";
}

Scott Dorman

There is no difference. string is the C# alias to String (which is really System.String). When the code compiles, all of your string types are converted to System.String in the IL. Personally, I prefer using string when I am typing a variable and String when I am acessing static members of the class. This is only personal preference as I think it makes the code easier to follow. There is nothing wrong with code like:

bool empty = string.IsNullOrEmpty("");

instead of

bool empty = String.IsNullOrEmpty("");

Scott Dorman

Microsoft® MVP - Visual C# | MCPD President - Tampa Bay IASA [Blog][Articles][Forum Guidelines]

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humayunlalzad

Why is the ref keyword added to String in this example. Isn't string a reference type already? I thought ref is only to make value types behave like reference types.

_Q12_

thanks....now I see. :-O

Scott Dorman

Glad to help.

Scott Dorman

Microsoft® MVP - Visual C# | MCPD President - Tampa Bay IASA [Blog][Articles][Forum Guidelines]

Hey, hey, hey. Don't be mean. We don't have to be mean because, remember, no matter where you go, there you are. - Buckaroo Banzai

_Q12_

look over this file and tell me how are you thinking in improve it ! I spend an entire night at it. The idea is to have a MAP (on the paper) and rapidly look over it and "remember" what i must to put when I need it. it's like a pocket reminder(a very tiny little map). http://www.sendspace.com/file/p56n1r of course in time must be the answer....if any...hope so... :) thanks again.

PIEBALDconsult

Scott Dorman wrote:

I prefer using string when I am typing a variable and String when I am acessing static members of the class.

Me too, except I type System.String.

murktinez

I'm pretty sure the only reason they have a the String class is because Java has a String class.

Saksida Bojan

humayunlalzad wrote:

Why is the ref keyword added to String in this example. Isn't string a reference type already? I thought ref is only to make value types behave like reference types.

I realy don't know about string, but i must have put into where i have struct type.

Luc Pattyn

Hi, I suggest you run something similar to this:

string str="aha";
log(str);
func1(str);
log(str);
func2(ref str);
log(str);

private void func1(String str) {str = "Changed"; log("1 "+str);}
private void func2(ref String str) {str = "Changed";log("2 "+str); }
private void log(string s) {Console.WriteLine(s);}

and think about why it behaves the way it does. :)

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Luc Pattyn

as System.Boolean.True hasn't been provided, do you also type System.Boolean.Parse(System.Boolean.TrueString) instead of true? :-D

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PIEBALDconsult

Don't tempt me; every once in a while I think about not using any of the aliases at all (they're all just syntactic sugar after all). Unfortunately they're required to specify base types for Enumerations :mad: .

Luc Pattyn

I have great news for you: System.String System.String System.String The second one has "lang=none" in the CODE tag. :)

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Lost User

Cool, is stuff like that documented somewhere? (am I just bad at searching?)

Luc Pattyn

I trust it is, however for harmless things like that, I just experiment a bit. I always allow for a few minutes of heuristics before taking the scientific route. :)

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PIEBALDconsult

Yes, Chris enlightened me about that a day or two ago. I still say that text should be the default.