Convert Arraylist into string in vb.net

Question

How do I convert an arraylist into a string of comma delimated values in vb.net

I have an arraylist with ID values

arr(0)=1
arr(1)=2
arr(2)=3

I want to convert it into a string

Dim str as string=""
str="1,2,3"

Answer 1

str = string.Join(",", arr.ToArray());

If you need to convert the List to string[] before the string.Join you can do

Array.ConvertAll<int, string>(str.ToArray(), new Converter<int, string>(Convert.ToString));

So...

str = string.Join(",", Array.ConvertAll<int, string>(str.ToArray(), new Converter<int, string>(Convert.ToString)));