Generics without direct instantiation

[Mark Rae]

Hi,

This is just for my own interest - I don't actually want to do it, I'm just
curious to know if it's possible...

Say we have the following method which accepts a List<string>...

private void MyMethod(List<stringplstMyList)
{
...
}

We could make a call to MyMethod like this:

List<stringlstMyList = new List<string>();
lstMyList.Add("This is a string");
MyMethod(lstMyList);
However, although it might not be particularly elegant, we could also do the
following:

MyMethod(new List<string>(new string[] { "This is a string" });

This made me wonder if it would be possible to pass a Dictionary<string,
stringvariable in the same way e.g.

private void MyMethod(Dictionary<stringpdicMyDictionary)
{
...
}

Dictionary<string, stringdicMyDictionary = new Dictionary<string,
string>();
dicMyDictionary.Add("This is a key", "This is a value");
MyMethod(dicMyDictionary);

Could we also do something like MyMethod(new Dictionary<string,
string>(...................);

[Jon Skeet [C# MVP]]

Mark Rae <ma**@markNOSPAMrae.comwrote:

This is just for my own interest - I don't actually want to do it, I'm just
curious to know if it's possible...

<snip>

Could we also do something like MyMethod(new Dictionary<string,
string>(...................);

I'm not sure exactly what you're asking. You could certainly call
MyMethod(new Dictionary<string,string>());

or use any of the other constructors of Dictionary<K,V- but there
aren't any constructors which take an IEnumerable in the same way that
List<Tdoes.

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too

[Mark Rae]

"Jon Skeet [C# MVP]" <sk***@pobox.comwrote in message
news:MP************************@msnews.microsoft.c om...

I'm not sure exactly what you're asking. You could certainly call
MyMethod(new Dictionary<string,string>());

Yes, but that would pass an empty Dictionary object...

or use any of the other constructors of Dictionary<K,V- but there
aren't any constructors which take an IEnumerable in the same way that
List<Tdoes.

OK - I think that answers my question - thanks...

[=?ISO-8859-1?Q?G=F6ran_Andersson?=]

Mark Rae wrote:

Hi,

This is just for my own interest - I don't actually want to do it, I'm just
curious to know if it's possible...

Say we have the following method which accepts a List<string>...

private void MyMethod(List<stringplstMyList)
{
...
}

We could make a call to MyMethod like this:

List<stringlstMyList = new List<string>();
lstMyList.Add("This is a string");
MyMethod(lstMyList);
However, although it might not be particularly elegant, we could also do the
following:

MyMethod(new List<string>(new string[] { "This is a string" });

This made me wonder if it would be possible to pass a Dictionary<string,
stringvariable in the same way e.g.

private void MyMethod(Dictionary<stringpdicMyDictionary)
{
...
}

Dictionary<string, stringdicMyDictionary = new Dictionary<string,
string>();
dicMyDictionary.Add("This is a key", "This is a value");
MyMethod(dicMyDictionary);

Could we also do something like MyMethod(new Dictionary<string,
string>(...................);

No, there is no constructor for a dictionary that takes an array.

--
Göran Andersson
_____
http://www.guffa.com

[David Browne]

"Mark Rae" <ma**@markNOSPAMrae.comwrote in message
news:eB*************@TK2MSFTNGP06.phx.gbl...

"Jon Skeet [C# MVP]" <sk***@pobox.comwrote in message
news:MP************************@msnews.microsoft.c om...

>I'm not sure exactly what you're asking. You could certainly call
MyMethod(new Dictionary<string,string>());

Yes, but that would pass an empty Dictionary object...

>or use any of the other constructors of Dictionary<K,V- but there
aren't any constructors which take an IEnumerable in the same way that
List<Tdoes.

OK - I think that answers my question - thanks...

This is another good reason not to declare methods that accept the concrete
generic collections. If you declare MyMethod as

void MyMethod(IDictionary<string,stringmyDictionary)
or
void MyMethod(IList<stringmyList)

Then you can create new types whose constructors you control to pass in for
convenience.

David

[Sir C4]

On Mar 3, 5:14 am, "Mark Rae" <[e-mail]:

Hi,

This is just for my own interest - I don't actually want to do it, I'm just
curious to know if it's possible...

Say we have the following method which accepts a List<string>...

private void MyMethod(List<stringplstMyList)
{
...

}

We could make a call to MyMethod like this:

List<stringlstMyList = new List<string>();
lstMyList.Add("This is a string");
MyMethod(lstMyList);

However, although it might not be particularly elegant, we could also do the
following:

MyMethod(new List<string>(new string[] { "This is a string" });

This made me wonder if it would be possible to pass a Dictionary<string,
stringvariable in the same way e.g.

private void MyMethod(Dictionary<stringpdicMyDictionary)
{
...

}

Dictionary<string, stringdicMyDictionary = new Dictionary<string,
string>();
dicMyDictionary.Add("This is a key", "This is a value");
MyMethod(dicMyDictionary);

Could we also do something like MyMethod(new Dictionary<string,
string>(...................);

I think what you're trying to do will be possible with the new 3.0 c#
specification.

[Mark Rae]

"Sir C4" <Va*******@gmail.comwrote in message
news:11**********************@i80g2000cwc.googlegr oups.com...

I think what you're trying to do

As I mentioned, I'm not actually trying to do this - it was just to satisfy
my curiosity...

will be possible with the new 3.0 c# specification.

Oh really...? I'll have a look - thanks for the tip...