LINQ 101 question

[Mike P]

In this LINQ example, how do you get at the values within the groupings?

string[] anagrams = {"from", "salt", "earn ", "last ", "near ", "form
"};

var orderGroups = anagrams.GroupB y(
w =w.Trim(),
new AnagramEquality Comparer());


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[Jon Skeet [C# MVP]]

Re: LINQ 101 question

On Aug 20, 4:46 pm, Mike P <mike.p...@gmai l.comwrote:

In this LINQ example, how do you get at the values within the groupings?
>
string[] anagrams = {"from", "salt", "earn ", "last ", "near ", "form
"};
>
        var orderGroups = anagrams.GroupB y(
                    w =w.Trim(),
                    new AnagramEquality Comparer());

GroupBy returns an IGrouping (IIRC) which has a Key property and
implements IEnumerable<Tfo r the appropriate T - so you typically
just use "foreach" over it.

Here's an example:
using System;
using System.Collecti ons.Generic;
using System.Linq;

class Test
{
static void Main()
{
string[] strings = { "These", "strings", "will",
"be", "grouped", "by", "length", "and", "then",
"displayed" , "in", "their", "groups" };

var groups = strings.GroupBy (x =x.Length);

foreach (var group in groups)
{
Console.WriteLi ne("Words of length: {0}", group.Key);
foreach (var word in group)
{
Console.WriteLi ne(" {0}", word);
}
}
}
}

Jon

[vbMark]

Re: LINQ 101 question

"Jon Skeet [C# MVP]" <skeet@pobox.co mwrote in news:05bf5f2b-589f-44db-
be15-bb0667c74261@m4 5g2000hsb.googl egroups.com:

On Aug 20, 4:46 pm, Mike P <mike.p...@gmai l.comwrote:

>In this LINQ example, how do you get at the values within the

groupings?

>>
>string[] anagrams = {"from", "salt", "earn ", "last ", "near ", "form
>"};
>>
>        var orderGroups = anagrams.GroupB y(
>                    w =w.Trim(),
>                    new AnagramEquality Comparer());

>
GroupBy returns an IGrouping (IIRC) which has a Key property and
implements IEnumerable<Tfo r the appropriate T - so you typically
just use "foreach" over it.
>
Here's an example:
using System;
using System.Collecti ons.Generic;
using System.Linq;
>
class Test
{
static void Main()
{
string[] strings = { "These", "strings", "will",
"be", "grouped", "by", "length", "and", "then",
"displayed" , "in", "their", "groups" };
>
var groups = strings.GroupBy (x =x.Length);
>
foreach (var group in groups)
{
Console.WriteLi ne("Words of length: {0}", group.Key);
foreach (var word in group)
{
Console.WriteLi ne(" {0}", word);
}
}
}
}
>
Jon
>

What if I only want the first item and do not want to do a foreach?

I want to do something like this:

string myString = strings[0];

But that is not an option.

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[Peter Duniho]

Re: LINQ 101 question

On Thu, 21 Aug 2008 12:45:38 -0700, vbMark <no@email.comwr ote:

What if I only want the first item and do not want to do a foreach?
>
I want to do something like this:
>
string myString = strings[0];
>
But that is not an option.

Try the System.Linq.Enu merable.First() method. For example, if you want
the group of the shortest words:

Console.WriteLi ne("The shortest words have {0} characters. They
are:", groups.First(). Key);
foreach (var word in groups.First())
{
Console.WriteLi ne(" {0}", word);
}

Pre-LINQ, you could of course always just put a "break" at the bottom of
your "foreach()" loop to ensure that you only ever process the first
element. But LINQ makes it nicer. :)

Pete