Splitting a collection with LINQ

1
votes

I'm sure there's an easy way to do this but I can't come up with it...

I have a collection with a Group string field. What I'd like to do is split that collection into (n) number of collections for each Group. I'll end up with a loop similar to this:

foreach (var group in groups)
{
   foreach (var item in group)
   {
      //process item.
   }
}

Any guidance out there??? Thanks!

Edit for example:

Given this:

var people = new List();
people.Add(new Person { FirstName = "John", LastName = "Doe" });
people.Add(new Person { FirstName = "Jane", LastName = "Doe" });
people.Add(new Person { FirstName = "Bob", LastName = "Barker" });
people.Add(new Person { FirstName = "Billy", LastName = "Barker" });
people.Add(new Person { FirstName = "Billy", LastName = "Bob" });

I'd like to get a collection with 3 elements. Element 1 will be a collection of people (the Does), Element 2 will be a collection of people (The Barkers), Element 3 will be a collection with Billy Bob.

2
c#linq
Describe the collection element type a bit more. Elaborate with an example - sample input and expected output. - Gishu

2 Answers

5
votes

Maybe, GroupBy will help?

var grouped = groups.GroupBy(g => g.Group);
2
votes

EDIT: made it fit the example. We group people by their last name, iterate over the groups, then iterate over each person inside each group

var groupedCollection = from person in people
                        group person by person.LastName; // or use .GroupBy()
foreach (var group in groupedCollection)
{
    var lastName = group.Key;
    foreach (var person in group)
    {
        // do stuff with person
    }
}

Read up on more grouping samples here