What is the equivalent in VB.Net of the C# As keyword, as in
var x = y as String;
if (x == null) ...
A:
Dim x = TryCast(y, [String])
From: http://www.developerfusion.com/tools/convert/csharp-to-vb/
Dustin Laine
2010-03-15 20:22:46
+10
A:
It is TryCast:
Dim x As String = TryCast(y, String)
If x Is Nothing Then ...
Hans Passant
2010-03-15 20:23:46
+1 Although I believe `TryCast` is not **exactly** equivalent to `as` because `TryCast` doesn't work for value types?
MarkJ
2010-03-15 23:24:14
@Mark: The *as* operator doesn't work on value types in C# either.
Hans Passant
2010-03-16 00:11:22
@nobugz: Well it works for nullable value types... You can do: var x = y as int?; if (x == null) ... so you should be able to do Dim x = TryCast(y, System.Nullable(Of Integer)) in VB
JoelFan
2010-03-16 01:41:51
@JoelFan, @nobugz. Oops. Let's try again. I believe `as` can convert value types into **nullable** types but `TryCast` can't? http://stackoverflow.com/questions/746767/how-to-acheive-the-c-as-keyword-for-value-types-in-vb-net/746914#746914
MarkJ
2010-03-16 13:52:27
This only works in very select cases because C# automatically applies a boxing conversion to "y". It cannot convert, say, a double to an int?
Hans Passant
2010-03-16 15:19:49
+3
A:
Trycast is what you're looking for.
Dim x = TryCast(y, String)
Morten Anderson
2010-03-15 20:23:57
+1
A:
Here you go:
C# code:
var x = y as String;
if (x == null) ...
VB.NET equivalent:
Dim x = TryCast(y, String)
If (x Is Nothing) ...
Alex Essilfie
2010-03-16 01:12:44