Convert Dictionary into structured format string

Question

I have a Dictionary object declared as var as Dictionary(of String, String).

I am trying to utilize the LINQ extensions available to the Generic Collection but am only getting the non-extension methods.

I need to turn the Dictionary collection into a string with the following pattern: key1=val1, key2=val2, ..., keyn=valn

Thought at first doing a foreach loop would hit the spot except the fact that i am programmers-block.

What i have so far, but doubt its the best logic pattern for producing this:

Public Overrides Function ToString() As String
    Dim ret As String = ""
    For Each kv As KeyValuePair(Of String, String) In Me._set
        If ret <> String.Empty Then
            ret &= ", "
        End If

        ret &= String.Format("{0}={1}", kv.Key, kv.Value)
    Next

    Return ret
End Function

And for some reason even though i have imported the System.Core & System.Linq libraries into the project none of the extended LINQ extensions are showing up in my dev-env intellisense. So for now, unless someone could help me get the LINQ extensions to show up in Intellisense, they are out of the question.

Found the problem with the LINQ extensions not showing up, so they are back on the table ;)

I would have written Linq like this (sorry for the C#-vb.net soup...) var ret = String.Join(",",Me._set.Select(kvp=>String.Format("{0}={1}",kvp.Key, kvp.Value).ToArray()); — jbl, Nov 28 '12 at 16:58
put that as an answer....and i do enough C# development to understand it. Just more comfortable with VB.Net. — GoldBishop, Nov 28 '12 at 17:00
The .net gurus seem to prefer vb.net over C#. They can't be wrong. I think I'm just the turbo-pascal generation, with semi-colons and curly braces ;-) — jbl, Nov 28 '12 at 17:16

jbl · Accepted Answer · 2019-11-20T08:08:02.567

10

I would have written the whole method block with Linq like this (sorry for the C#-vb.net soup...)

c-sharp

return String.Join(",",Me._set.Select(kvp=>String.Format("{0}={1}",kvp.Key, kvp.Value).ToArray());

Also, I don't really know what _set is. Maybe you'll have to cast :

c-sharp:

return String.Join(",", Me._set.Cast<KeyValuePair<String,String>>().Select(kvp=>String.Format("{0}={1}",kvp.Key, kvp.Value).ToArray());

vb.net:

return String.Join(", ", Me.Select(Function(kvp) String.Format("{0}={1}", kvp.Key, kvp.Value)).ToArray())

Hope this will help,

edited Nov 20 '19 at 08:08

answered Nov 28 '12 at 17:11

jbl

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1

worked like a charm once i translated to VB.Net. Conversion equivalent: `String.Join(", ", Me.Select(Function(kvp) String.Format("{0}={1}", kvp.Key, kvp.Value).ToArray()))` – GoldBishop Nov 28 '12 at 18:23
`_set` is private variable which is the `Dictionary(Of String, String)` – GoldBishop Nov 28 '12 at 18:45
Changed it so the class was extended from `Dictionary(Of String, STring)` as it made operating against the collection easier. – GoldBishop Nov 28 '12 at 18:47
2

I found a parenthesis error in vb.net. It should be `return String.Join(", ", Me.Select(Function(kvp) String.Format("{0}={1}", kvp.Key, kvp.Value)).ToArray())` – Matt Roy Feb 06 '18 at 15:17
the parenthesis error caused it to instead print as System.char[] – cheft Jun 26 '19 at 15:51

Steven Doggart · Answer 2 · 2017-08-30T14:48:41.313

6

As far as your non-LINQ loop goes, I would recommend doing it like this:

Public Overrides Function ToString() As String
    Dim items As New List(Of String)(_set.Count)
    For Each pair As KeyValuePair(Of String, String) In _set
        items.Add($"{pair.Key}={pair.Value}"))
    Next
    Return String.Join(", ", items)
End Function

With LINQ, you could do it like this:

Public Overrides Function ToString() As String
    Return String.Join(", ", _set.Select(Function(pair) $"{pair.Key}={pair.Value}"))
End Function

edited Aug 30 '17 at 14:48

answered Nov 28 '12 at 16:53

Steven Doggart

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what would you do with LINQ? – GoldBishop Nov 28 '12 at 16:59
I wouldn't :) I'm stuck in VS 2005, so I'm not that familiar with it. – Steven Doggart Nov 28 '12 at 17:00
1

DOH....i have 3 versions to play with 2k8, 2010, & (clients) 2012. Left 2k5 as soon as 2k8 came out for SL2/3 development – GoldBishop Nov 28 '12 at 17:12
@jbl ;p~ in your General Direction – GoldBishop Nov 28 '12 at 20:31
Well, now that we're up to VS 2017, I figured it was high-time I updated my answer to reflect the latest technology. The examples in my answer now demonstrate the use of LINQ as well as using interpolated string literals rather than `String.Format`. – Steven Doggart Aug 30 '17 at 14:50

score 3 · Answer 3 · answered Nov 28 '12 at 22:29

3

VB.net syntax:

Dim dic As New Dictionary(Of String, String)() From {
            {"a", "1"},
            {"b", "2"},
            {"c", "3"},
            {"d", "4"}
            }

Dim s As String = String.Join(",", dic.Select(Function(pair) String.Format("{0}={1}", pair.Key, pair.Value)).ToArray())

answered Nov 28 '12 at 22:29

Steve

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Same exact code as @jbl posted above. Please add to the thread dont just put a brighter shine on something already suggested. – GoldBishop Nov 29 '12 at 14:19
1

When i posted this there was only c# syntax in jbl's answer, i am surprised you think that is somehow worth a downvote, but i can live with it! – Steve Nov 29 '12 at 15:10
1

@GoldBishop That is not how SO works. People edit their answers and it may not even be apparent that they have. You will find multiple similar answers. There is prbably little or no time difference. On meta it mentions that downvotes should be on correctness of an answer rtaken in isolarion. – Fionnuala Dec 01 '12 at 11:03
`dic.select` didn't work for me. Perhaps because I'm declaring it as a general `object` – Bernardo Dal Corno Feb 01 '18 at 17:50

Convert Dictionary into structured format string

3 Answers3

c-sharp

c-sharp:

vb.net:

Linked