How do I create a comma delimited string from an ArrayList?

c# vb.net parsing
Dillie-O picture Dillie-O · Oct 17, 2008 · Viewed 135k times · Source

I'm storing an ArrayList of Ids in a processing script that I want to spit out as a comma delimited list for output to the debug log. Is there a way I can get this easily without looping through things?

EDIT: Thanks to Joel for pointing out the List(Of T) that is available in .net 2.0 and above. That makes things TONS easier if you have it available.

Answer

Dillie-O picture Dillie-O · Oct 17, 2008

Yes, I'm answering my own question, but I haven't found it here yet and thought this was a rather slick thing:

...in VB.NET:

String.Join(",", CType(TargetArrayList.ToArray(Type.GetType("System.String")), String()))

...in C#

string.Join(",", (string[])TargetArrayList.ToArray(Type.GetType("System.String")))

The only "gotcha" to these is that the ArrayList must have the items stored as Strings if you're using Option Strict to make sure the conversion takes place properly.

EDIT: If you're using .net 2.0 or above, simply create a List(Of String) type object and you can get what you need with. Many thanks to Joel for bringing this up!

String.Join(",", TargetList.ToArray())

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