Trouble Converting code due to dual parentheses

Question

I am trying to convert some old legacy from VB to C# but I am running into an issue with a particular area regarding dual parentheses

Dim _atts As List(Of String()) = List(Of String())
Dim tmp() As String = Me._atts.Item(AttNo)(ValNo).Split(_SVM)

I don't understand how I would write the (attNo)(valNo) in C#

I have tried the following but with no luck

List<string[]> _atts = new List<string[]>();
string[] tmp = this._atts[attNo](valNo).Split(_SVM);

Can someone enlighten me as to what the dual parenthesis actually do in VB?

Thanks

I dont remember VB at all but maybe its a 2d/jagged array syntax? Like `someArray[1][2]` — maccettura, Sep 24 '18 at 15:59
Depends on what `_atts.Item` is..., more than likely a 2d array as @maccettura mentioned. Try `string[] tmp = this._atts[attNo][valNo].Split(_SVM);` — Trevor, Sep 24 '18 at 16:07
ahh no way, it was staring me in the face, never had experience with 2d/jagged arrays — Corbin Taylor, Sep 24 '18 at 16:08
It is the vb.net way to refer to an `item(row_index)(column_index)` inside a list — Simo, Sep 24 '18 at 16:25
This is vb.Net, not vb6 for sure. As the first comment and current answer states - parenthesis in this context is used so indicate an indexer - so when translating to c# you convert them to square brackets - `string[] tmp = this._atts[attNo][valNo].Split(_SVM);` — Zohar Peled, Sep 24 '18 at 16:48

Alexander Ross · Accepted Answer · 2018-09-26T18:58:13.813

3

In VB.Net the parenthesis in this context is used to access and iterate the values of an array (access the indexer). So if you have the member variable "exampleArray" with the values {"I", "Like", "Coding"}, it can be accessed like:

VB

Dim tmpStr as String = Me.exampleArray(1);

C#

string tmpStr = this.exampleArray[1];

now tmpStr contains the value "Like"

Now consider that you have an array "outerArray" that contains {exampleArray, someOtherArray}. If you want to get to the value "Like" you will need to index both arrays:

VB

Dim tmpStr as String = outerArray(0)(1)

C#

string tmpStr = outerArray[0][1];

The first set of square brackets (c#) or parenthesis (VB) is used to index "outerArray" to get access to "exampleArray". Then the second set of square brackets or parenthesis is used to access the value "Like" within "exampleArray".

Ref: Micorsoft Programming Guide - Arrays

edited Sep 26 '18 at 18:58

answered Sep 24 '18 at 16:28

Alexander Ross

56
3

Plus one. Good answer. One wrinkle: It seems from the OP's question that in this case, the "outer" part is a `List(Of T)` rather than an array. But I think your C# code is also correct for a `List(Of T)` containing arrays. – MarkJ Sep 25 '18 at 12:23
Good answer thanks – Corbin Taylor Sep 26 '18 at 12:06
@MarkJ you are correct, however, than bit of context was added to the question after I answered. Good catch though. – Alexander Ross Sep 26 '18 at 18:55
@AndrewMorton you are absolutely right. Changed it – Alexander Ross Sep 26 '18 at 18:58

Trouble Converting code due to dual parentheses

1 Answers1