[newbe] instantiating class variable in constructor

[Snaggy]

Hi, this is my first day using c# and I must say it's cool but data
types.. I'm not use to them (php...) they're driving me crazy.

I need to declare a class variable, but I don't know it's type since
it's passed to the constructor when the object is created. I'd like
something like this:

class MyClass
{

public MyClass(int attribute)
{
if (attributes == 1)
{
string myDeck = "something";
}
else if (attributes > 1)
{
int myDeck = "123";
}
}

public string tellMe() // by the way I'm saying string, but
it might be integer... what the..
{
return myDeck;
}
}


how can I solve this mess? Can anyone reassure me that this compulsory
typing isn't actually just a headache?

bye!
Luca(IT)

 

[Chris Shepherd]

Hi, this is my first day using c# and I must say it's cool but data
types.. I'm not use to them (php...) they're driving me crazy.

I need to declare a class variable, but I don't know it's type since
it's passed to the constructor when the object is created. I'd like
something like this: [...]
how can I solve this mess? Can anyone reassure me that this compulsory
typing isn't actually just a headache?

Well, generally you would want to strongly type your data where possible. Is
there a practical reason you could not simply provide two separate properties to
provide access to your different data types?

Alternately, you could define your variable as "object", ie:
private object myDeck;



Chris.

 

[Snaggy]

what do you mean 2 diff properties? I'd still have do declare my
variable after having constructed the object. Let me ask this, is it
possible to declare variable object wide (accessible through
this.varName) after having created the object? Or do I have to declare
them all and as object the typeToBeDefined ones?

(hope I explained myself..)

bye

 

[sloan]

if you don't know the type.. you can either use "object", (which is kinda
crappy)..or

Use a Generic. Here is a sample. (see below).

As far as "compulsary typing"...strong typing makes more maintainable code.
The time spent on code is maintenance, not development.




class MyClass<T>

{

private T _model = default (T);

public MyClass(T attribute)

{

_model = attribute;

}

public T FindIt()

{

return _model;

}

}





class Program

{

static void Main(string[] args)

{



MyClass<int> mc1 = new MyClass<int>(123);

int x = mc1.FindIt();

Console.WriteLine(Convert.ToString (x));

MyClass<Exception> mc2 = new MyClass<Exception>(new Exception("You can use
any object here with Generics!"));

Exception foundEx = mc2.FindIt();

Console.WriteLine( (foundEx.Message ));



MyClass<Guid> mc3 = new MyClass<Guid>(Guid.NewGuid());

Guid g = mc3.FindIt();

Console.WriteLine(g.ToString ("N"));



}

}

 

[Snaggy]

I'll study a bit on that.. for today I decided to change approach.
Let's make everything a Dictionary!

can you look at this code (cards' deck, with method to add card and
its attributes which might be 1 or more)


class Deck
{
Dictionary<string, string[]> myDeck = new Dictionary<string,
string[]>();

public string getAttribute(string name)
{
return myDeck[name][0];
}
public string getAttribute(string name, int attribute)
{
return myDeck[name][attribute];
}


public void addCard(string name, string attribute)
{
if (attribute.Contains(",")){
String[] attributes = attribute.Split(',');
myDeck.add(name, attributes); <---- HERE
}
else
{
String[] attributes = { attribute };
myDeck.add(name, attributes);
}
}

}


at the "HERE" I got this problem when tried to debug:

Error 1 'System.Collections.Generic.Dictionary<string,string[]>' does
not contain a definition for 'add' and no extension method 'add'
accepting a first argument of type
'System.Collections.Generic.Dictionary<string,string[]>' could be
found (are you missing a using directive or an assembly reference?) C:
\Documents and Settings\Proprietario\Documenti\Visual Studio
2008\Projects\CardSke\CardSke\Program.cs 30 24 CardSke


what's that??
bye

 

[Marc Gravell]

at the "HERE" I got this problem when tried to debug:
C# is case sensitive. Try Add(...)

Marc

 

[Snaggy]

C# is case sensitive. Try Add(...)

Marc

nope.. did it already

 

[Jon Skeet [C# MVP]]

nope.. did it already

If you've done it in both places already, it should compile. I took
your code, changed "add" to "Add" in both places, and added the
appropriate using directives, and it works fine.

Jon

 

[Snaggy]

If you've done it in both places already, it should compile. I took
your code, changed "add" to "Add" in both places, and added the
appropriate using directives, and it works fine.

Jon

yeah, it seems so... it must have been some other problem too, thanks!

anyway.
Returning to the main topic.. is it possible to define a variable
that'll be class accessible in a method?

 

[Jon Skeet [C# MVP]]

Returning to the main topic.. is it possible to define a variable
that'll be class accessible in a method?

No. You can only declare *local* variables in methods.

Jon