Question

I know that I can use FOR EACH to easily accomplish my goal below, however I run into this scenario a LOT and was wondering if there was a more elegant solution.

Class Foo
    Public X as String
    Public Y as Integer   
End Class

Dim c As New List(Of Foo) = GetFooItemsFromDatabase......

I want to get a comma delimited string of all the X’s in c. If I had a simple array of string called simpleArray I could do something like

dim s as String = String.Join(", ", simpleArray)

Is there a way of building simpleArray (LINQ, built in functions, etc) that will accomplish this instead of having to use FOR EACH and build it myself?

EDIT: It seems LINQ is the way to go. However converting the many suggestions from C# to VB yields the following which the compiler does not like.

Dim s As String = c.[Select](Function(myVal) myValue.X)

Answer 1

OK this is C#, so apologies, but you could use a little LINQ:

string.Join(", ", c.Select(c => c.X).ToArray());

The Select extension method allows you to project the output, you are basically taking an enumerable of c and projecting it to an enumerable of X. You then call ToArray to translate your IEnumerable<string> into a string[] (in C# vernacular).

LINQ is fully supported in VB.NET and is well worth reading more into:

http://msdn.microsoft.com/en-us/library/bb763068.aspx

If you are new to it, the standard naming of “LINQ” tends to cover both the new syntax:

from name in names 
select name

And also its guise in extension methods:

.Select().Where().OrderBy(); //.etc()

A VB.NET LINQ source:

http://www.wrox.com/WileyCDA/Section/LINQ-Extension-Methods-with-Visual-Basic-2008.id-310907.html