Adding to a collection in Net vs VB6 ...

  • Thread starter Thread starter Mike
  • Start date Start date
M

Mike

Checking whether an item exists in a collection before adding it ... (Key is
always a string and in this case is the value as well)

As Net has a Contains method ... is the following a safe alternative to the
VB6 On Error Resume Next?

If Not colDs.Contains(sKey) Then
colIDs.Add(sKey, sKey)
End If

Thanks,
Mike
 
Checking whether an item exists in a collection before adding it ... (Key is
always a string and in this case is the value as well)

As Net has a Contains method ... is the following a safe alternative to the
VB6 On Error Resume Next?

If Not colDs.Contains(sKey) Then
colIDs.Add(sKey, sKey)
End If

Thanks,
Mike
Click to expand...

Well, assuming this is a Dictionary (Of String, Of String) you would
use:

If Not colDs.ContainsKey(sKey) Then
....
End If

And if it's a System.Collections.Hashtable - then the code is the same
:)
 
Mike,

In VB6 you have one collection (which is as well in VB for Net and not in
C#). However most of us here have the opinion that it is the only thing that
should be as possible avoided from the Net namespace Microsoft.VisualBasic
(this is a true part of Net).

In .Net there are endless collections, lists, special collections, generic
collections etc.

In this case you can start with the arraylist, however better is a simple
List(of String) because then the strings are easier to use.

http://msdn2.microsoft.com/en-us/library/6sh2ey19(vs.80).aspx

Cor
 
Thanks very much for all the replies.

The code which I'm converting from VB6 uses a number of simple collections
and the On Error Resume Next statement to handle duplicate keys. As I'm sure
you know, this was a common VB6 practice.

What I was wondering is whether the Net methods Contains/ContainsKey are
regarded as a safe alternative to the Resume Next error handling. It seems a
little too simple, so I was wondering if I'm missing some gotcha here ...
 
Mike,

The Resume next has *seldom* been a good handling of known situations
(As the try and catch are as well not).

The one you use now is preventing not wanted situations, whereabout you have
full control.

Cor
 
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