Collection to delimited string

Question

when I do

String.Join(";", lst.Items)

I get a string of object descriptors instead of item of values. But when I iterate the collection, I end up with a delimiter at the front or back and need to a Substring call afterwards.

    Dim res As String = "" 'or use stringbuilder
    For Each s As String In lst.Items
        s &= ";" & s
    Next
    res = res.Substring(1)

This applies to other cases as well where you want to turn a shared property within a collection into a delimited string. Is there a nice way to do this? Can I do this with LINQ and would it be faster?

no, ObjectCollections expose already the IList interface, but they contain Objects rather than strings. — aelgoa, Oct 11 '13 at 14:17

user247702 · Answer 1 · 2013-10-11T14:47:29.083

3

You'll have to convert the items to strings then:

String.Join(";", lst.Items.Select(Function(item) item.ToString()));

edited Oct 11 '13 at 14:47

answered Oct 11 '13 at 14:21

user247702

23,641
15
110
157

2

+1, but technically, I'd refer to `ToString` as *converting*, not *casting*. `DirectCast` is *casting*. Pretty much everything else in VB.NET, including `CType` and `ToString`, could only be accurately be described as converting. – Steven Doggart Oct 11 '13 at 14:39
ty, I picked dbasnett's as the answer cause I expect it to be a bit faster even than LINQ – aelgoa Oct 11 '13 at 21:25

score 1 · Accepted Answer · answered Oct 11 '13 at 14:52

1

How about

    Dim res As String = String.Join(";", lst.Items.OfType(Of String))

answered Oct 11 '13 at 14:52

dbasnett

11,334
2
25
33

score 0 · Answer 3 · edited May 23 '17 at 10:25

0

This does work:

    Dim col As New Collection
    col.Add("One")
    col.Add("Two")
    col.Add("Three")

    Dim res = String.Join(";", col.OfType(Of String))

See also this question

edited May 23 '17 at 10:25

Community

1
1

answered Oct 11 '13 at 14:14

dummy

4,256
3
25
36

The array is already made, I want to take a property of the elements into a delimited string, without explitl rebuilding – aelgoa Oct 11 '13 at 14:20
I added the building of the collection just as an example, because your question didn't contain which kind of collection your question is about. And a Collection is not the same as an array. – dummy Oct 14 '13 at 07:34

Collection to delimited string

3 Answers3