Iteratate Dictionay of List

[=?Utf-8?B?THVpZ2k=?=]

Hi all,
I have a dictionary like this:

Dictionary<List <string>, List<string>>

How can I iterate in it?

Thanks very much.
--
Luigi

[Marc Gravell]

Re: Iteratate Dictionay of List

Well, what do you want to iterate? Each key (a List<string>) could have
multiple valies - do you just want the values?

With C# 3.0 / .NET 3.5, SelectMany is an option, but I guess (last post)
that this isn't an option. So you'll just need a few nested foreach loops.

Marc

[=?Utf-8?B?THVpZ2k=?=]

Re: Iteratate Dictionay of List

"Marc Gravell" wrote:

Well, what do you want to iterate? Each key (a List<string>) could have
multiple valies - do you just want the values?
>
With C# 3.0 / .NET 3.5, SelectMany is an option, but I guess (last post)
that this isn't an option. So you'll just need a few nested foreach loops.

Yes, I'm using C# 2.0, so many useful options are prohibited for me.
What I'd like is to obtain the collection of strings for every string of the
first List in my dictionary.

Luigi

[Marc Gravell]

Re: Iteratate Dictionay of List

Yes, I'm using C# 2.0, so many useful options are prohibited for me.

What I'd like is to obtain the collection of strings for every string of the
first List in my dictionary.

Can you show that with a simple example?

i.e.
"if the data was as bloe, then I want {your bit here}

item 1: key (list) "a", "b"
value (list) "c", "d", "e"
item 2: key (list) "f"
value (list) "g", "h"

Marc

[=?Utf-8?B?THVpZ2k=?=]

Re: Iteratate Dictionay of List

"Marc Gravell" wrote:

Yes, I'm using C# 2.0, so many useful options are prohibited for me.
What I'd like is to obtain the collection of strings for every string of the
first List in my dictionary.

>
Can you show that with a simple example?
>
i.e.
"if the data was as bloe, then I want {your bit here}
>
item 1: key (list) "a", "b"
value (list) "c", "d", "e"
item 2: key (list) "f"
value (list) "g", "h"

I can't use the ContainsKey method of my Dictionary passing a List<string>
that is contained.

L

[Marc Gravell]

Re: Iteratate Dictionay of List

See below; I expect the problem is that you are passing a *different*
list that has the same data. By default, the lists are compared for
object (reference) equality. It is possible to override this behavior by
performing a custom comparison (so that two lists with the same contents
are treated as equal). Let me know if you need this.

Marc

class Program
{
static void Main()
{
Dictionary<List <string>, List<string>loo kup = new
Dictionary<List <string>, List<string>>() ;
lookup.Add(Wrap ("a", "b"), Wrap("c", "d", "e"));
lookup.Add(Wrap ("f"), Wrap("g", "h"));

List<stringfirs tKey = null;
foreach (KeyValuePair<L ist<string>, List<string>pai r in lookup)
{
if (firstKey == null) firstKey = pair.Key;
Write(pair.Key, "Key");
Write(pair.Valu e, "Value");
}

if (lookup.Contain sKey(firstKey))
{
List<stringvalu e = lookup[firstKey];
Write(value, "Value By Key");
}
}
static void Write<T>(List<T list, string caption)
{
Console.WriteLi ne(caption);
foreach (T t in list)
{
Console.WriteLi ne("\t{0}", t);
}
}
static List<TWrap<T>(p arams T[] args)
{
return new List<T>(args);
}
}

[Marc Gravell]

Re: Iteratate Dictionay of List

To treat different lists (with the same contents) as equal, you need to
provide a custom IEqualityCompar er<Tto the dictionary's constructor.

The following should suffice, used with:

... lookup = new Dictionary<List <string>,
List<string>>(L istComparer<str ing>.Default);

Marc

class ListComparer<T: IEqualityCompar er<List<T>>
{
private readonly IEqualityCompar er<TitemCompare r;
public static readonly ListComparer<TD efault = new ListComparer<T> ();
public ListComparer() : this(null) { }
public ListComparer(IE qualityComparer <TitemCompare r)
{
this.itemCompar er = itemComparer ?? EqualityCompare r<T>.Default;
}

bool IEqualityCompar er<List<T>>.Equ als(List<Tx, List<Ty)
{
if (ReferenceEqual s(x, y)) return true;
int len;
if (x == null || y == null || (len = x.Count) != y.Count)
return false;
for (int i = 0; i < len; i++)
{
if (!itemComparer. Equals(x[i], y[i])) return false;
}
return true;
}

int IEqualityCompar er<List<T>>.Get HashCode(List<T list)
{
if (list == null) return 0;
int agg = 3;
foreach (T item in list)
{
agg *= 13;
agg += 7 * itemComparer.Ge tHashCode(item) ;
}
return agg;
}
}

[Peter Morris]

Re: Iteratate Dictionay of List

Are you sure you don't want something like

Dictionary<stri ng, Dictionary<stri ng, string>>

Your data structure seems quite useless to me. What are you intending to
store within it, and how do you intend to use that data?


--
Pete
====

http://mrpmorris.blogspot.com

http://www.capableobjects.com

[=?Utf-8?B?THVpZ2k=?=]

Re: Iteratate Dictionay of List

"Marc Gravell" wrote:

See below; I expect the problem is that you are passing a *different*
list that has the same data. By default, the lists are compared for
object (reference) equality. It is possible to override this behavior by
performing a custom comparison (so that two lists with the same contents
are treated as equal). Let me know if you need this.
>
Marc
>
class Program
{
static void Main()
{
Dictionary<List <string>, List<string>loo kup = new
Dictionary<List <string>, List<string>>() ;
lookup.Add(Wrap ("a", "b"), Wrap("c", "d", "e"));
lookup.Add(Wrap ("f"), Wrap("g", "h"));
>
List<stringfirs tKey = null;
foreach (KeyValuePair<L ist<string>, List<string>pai r in lookup)
{
if (firstKey == null) firstKey = pair.Key;
Write(pair.Key, "Key");
Write(pair.Valu e, "Value");
}
>
if (lookup.Contain sKey(firstKey))
{
List<stringvalu e = lookup[firstKey];
Write(value, "Value By Key");
}
}
static void Write<T>(List<T list, string caption)
{
Console.WriteLi ne(caption);
foreach (T t in list)
{
Console.WriteLi ne("\t{0}", t);
}
}
static List<TWrap<T>(p arams T[] args)
{
return new List<T>(args);
}
}
>

Thank you Marc, very interesting.
Now I'm trying to using this code in my project.

Luigi

[=?Utf-8?B?THVpZ2k=?=]

Re: Iteratate Dictionay of List

In the first string I have a name of check.
In the inner dictionary I have a list of objects that have to match together.
For example

"check1" is the key of the outer dictionary.

then I have "value1", "value2" is the key of the inner dic, and
"innervalue 1", "innervalue 2", "innervalue 3" are the values.

Luigi

[=?Utf-8?B?THVpZ2k=?=]

Re: Iteratate Dictionay of List

Another question Marc.
How can I write a methods that returns me the composition of the inner
dictionary?
For example, for the first KeyValuePair of the first List<stringI'd like
to obtain the List<stringvalu e of the inner dictionary.

Luigi

[Peter Morris]

Re: Iteratate Dictionay of List

Looks more like you want this...

Dictionary<stri ng, Dictionary<stri ng, List<string>>>


Take a look at this....


using System;
using System.Collecti ons.Generic;
using System.Text;

namespace ConsoleApplicat ion7
{
class Program
{
static void Main(string[] args)
{
Dictionary<stri ng, Dictionary<stri ng, List<string>>ch ecks = new
Dictionary<stri ng, Dictionary<stri ng, List<string>>>( );

for (int checkNumber = 0; checkNumber < 10; checkNumber++)
{
checks.Add("Che ck" + checkNumber.ToS tring(), CreateCheck());
}

foreach (var currentCheck in checks)
{
Console.WriteLi ne("CurrentChec k: " + currentCheck.Ke y);
foreach (var currentValue in currentCheck.Va lue)
{
Console.WriteLi ne(" Current value: " + currentValue.Ke y);
foreach (var currentInnerVal ue in currentValue.Va lue)
Console.WriteLi ne(" Current inner value: " + currentInnerVal ue);
Console.ReadLin e();
}
}

}

private static Dictionary<stri ng, List<string>Cre ateCheck()
{
var result = new Dictionary<stri ng, List<string>>() ;
for (int valueNumber = 0; valueNumber < 10; valueNumber++)
{
result.Add("Val ue" + valueNumber.ToS tring(), CreateInnerValu es());
}
return result;
}

private static List<stringCrea teInnerValues()
{
return new List<string>(ne w string[] { "One", "Two", "Three" });
}

}
}

[=?Utf-8?B?THVpZ2k=?=]

Re: Iteratate Dictionay of List

Having this code:

Dictionary<stri ng, Dictionary<stri ng[], string[]>outerCheck =
new Dictionary<stri ng, Dictionary<stri ng[], string[]>>();

Dictionary<stri ng[], string[]innerCheck = new Dictionary<stri ng[],
string[]>();
string[] vociReference1 = {"Tava|a", "Tavb|b"};
string[] vociBalancing1 = {"Tavm|m", "Tavn|n"};

innerCheck.Add( vociReference1, vociBalancing1) ;

outerCheck.Add( "Check1", innerCheck);

Dictionary<stri ng[], string[]innerCheckTest = new Dictionary<stri ng[],
string[]>();
innerCheckTest = outerCheck["Check1"];

Dictionary<stri ng[], string[]>.KeyCollecti on keys = innerCheckTest. Keys;

string[] myKeys;

I can't populate this array.
What's wrong?

L