Coalesce Operator And Conditional Operator In .NET?
Mar 10, 2009Possible Duplicate: Is there a conditional ternary operator in VB.NET?
Can we use Coalesce operator(??) and conditional ternary operator(:) in VB.NET as in C#?
Possible Duplicate: Is there a conditional ternary operator in VB.NET?
Can we use Coalesce operator(??) and conditional ternary operator(:) in VB.NET as in C#?
i'm afraid that this is a stupid question, but i must assume that i have programmed VB.Net too long and now can't figure out how to convert this C# null coalescing operator into VB.Net:
if( Convert.ToBoolean(ViewState[tp.UniqueID + "_Display"] ?? true) == false ){}
I know the IIF-Function but i'm not sure how to use it here and if it gives the correct result(in IIF both expressions are being evaluated). Please help to shed light on the dark.EDIT: if you want to see the source of this: forums.asp.net There you can see a solution that generates a Option Strict On disallows implicit conversions from 'Object' to 'Boolean' compiler exception.
I have a class Customer which contains the property Extensions which in turn contains the property Any. I tried to do: Dim room = If(customer.Extensions.Any.ElementAt(0).InnerText, Nothing) but it threw an error when it did not find an Extension element in the incoming xml. I thought it would return nothing once it saw that the first expression was Nothing. Do I have to do a multiple if statement in this case?
View 1 RepliesIn Perl (and other languages) a conditional ternary operator can be expressed like this:my $foo = $bar = $buz ? $cat : $dog;Is there a similar operator in VB.NET?
View 2 RepliesSo I'm writing the equality operator overload (Operator =())for a custom object, and the resulting mess of If conditionals is just an eyesore. But so far, it seems like the only sane way to check the values to as to match the specific behavior of this object.
The rules are:Num1 is required, period, and both the left and right operands and must be equal for True. Else, False.Num2 is optional, but if specified, must be present for both the left and right operands, and must be equal for True. Else, False.Num3 is optional, but can only be specified if Num2 is also present. Else, False.Num3, if specified, must be present for both the left and right operands, and must be equal for True. Else, False.
[Code]..
I also know that I could cache elements of the checks into booleans and then use those to reduce the amount of text. But that seems like a waste of cycles just for code readability. So I wanted to know if the SO community had better thoughts on reorganizing it, just in case I'm being too verbose with my checks.
I am tightening up my coding with the Option Strict set to ON. It has now produced alot of errors. An example of this is:
If AllocatedDGV.Rows(i).Cells("RoomNumber").Value = RoomsAvailableDGV.Rows(j).Cells("RoomName").Value Then
It gives me the following error: Option Strict On disallows operands of type Object for operator '='. Use the 'Is' operator to test for object identity.
I need to write an interface to get data to/from our data files.
We have a low level class that holds field values for each record read from the files.
This just holds two values, the value read from the file (DBValue) and the updated value that may need to be written back to the file (CurrentValue).
These values may be any of the standard value types (integer, date etc) or a string.
Either value (DBValue or CurrentValue) may be null if not defined.
I have written the class to manage this data which works fine while option strict is NOT on.
But we have an office policy of having option strict on all the time.
When I put option strict on, my object value comparisons fail with the error: "Option Strict On disallows operands of type Object for operator '='. Use the 'Is' operator to test for object identity."
Question, how should I change the following code to handle option strict on ...
This is all running on Visual Studio 2010
[Code]...
I want to perform equality comparison in VB.NET and cannot get it to work. Error: value of type Boolean can not be converted to System.Drawing.PointF
[code]...
What does the ! mean in the following code snippet?Availability is a table in an access database Family and Model are column headers in the table cmbFamily and cmbModel are combo boxes.
If Availability!family = cmbFamily.Text Then
cmbModel.Items.Add(Availability!model)
End If
add the models of as aircraft family to a combobox(cmbModel) using a selection from another combobox(cmbFamily).
whats do Or operator in Vb do when it is applied as follows eg
Dim returnValue As UInt32
Public Const RMA_VC_RET_NULL_PTR_PARAMETER = 1
returnValue = returnValue Or RMA_VC_RET_NULL_PTR_PARAMETER
what does the 3rd statement do?
Dim bteJustTheAddress As Byte bteJustTheAddress = RawData(2) And &H7F
RawData is a Byte Array and I know &H7F is the Hex 7F
came across this issue while converting a for loop in C# to VB.net I realized that the increment operators are not available in vb.net (++ and --)whereas i was able it do something like cnt +=1 .In VB, a STATEMENT cannot be just an EXPRESSION. why this doesn't work in the same way as it does in C#.
View 4 RepliesI want to know what is purpose of '' in vb ? I have this statement: frontDigitsToKeep 2 and I want to convert it to C#.
View 2 RepliesWhat scenarios would you consider operator overloading in .net?
View 5 RepliesI am trying to get data from my Access database using like operator. For example my ProducID contains NoteBook, Notes etc. Using like operator, I want to get them all shown if user types No etc.Like operator did not give any errors but it only shows record when I put full NoteBook (does not show for Notes offcourse)
View 2 Replieshow to use? operator Like in Bindigsource? for Exmaple :
BindingSource1.Filter=" Feild1 Like N'%" & TextBox1.text & "'%"
that Code is false,Becuse hase an error?
s it possible to use NOT IN operator in If Statement?i.e. If strPara NOT IN (strCompare1,strCompare2) then exit sub
View 17 RepliesIs there a ?: operator equivalent in .net? eg in java I can do:
[Code]...
I'd like to be able to do similar in VB.NET.
I'm converting vb code to c#There is enum from telerik library:
namespace Telerik.Windows.Controls
{
// Summary:
[code].....
Error1Operator '&' is not defined for types 'String' and 'System.Exception'.L:\Programming\thingy\Mail.vb3720thingy
not much else i can think to add here but it's making it hard to work...i'm using it like...
Dim Temp As String = "Hello" & vbCrLf & "Hi Again"
I'm having an error on the red font ...it says operator '+' not defined for type dbnull and type dbnull [code]...
View 7 RepliesBy Using
dv.RowFilter = "Convert([OIMainID], 'System.String') Like '" & OIMainIDTextBox.Text & "%'""
i'm almost getting the result i want. What i want is an exact match in the filter so if the box only contain the number 1 to will only show rows with the number 1 and not return say 12 13 14 etc etc, and vice versa for other numbers.
Is there any way to pass in an operator in VB.NET? I'm looking to reduce my lines of code and for two functions there is literally only an operator that is different.For example, I have two functions, Darken and Lighten. I'd like to get to a single function with as little code as possible. The only difference are Greater Than and Less Than operators.
Function Darken(ByVal clr1 As Color, ByVal clr2 As Color) As Color
Dim newR = If(clr2.R < clr1.R, clr2.R, clr1.R)
Dim newG = If(clr2.G < clr1.G, clr2.G, clr1.G)
[code].....
how do i randomize the operator?? i mean i wan the operator occur to be in random .i have to rush out my miniproject on next wednesday so i do ask the problem i meet here
View 5 Repliesi want to check if datasets have changes and after that use msgbox (vbYesNoCancel) when program closes ,when i wrote this code it had error "Operator 'Or' is not defined for types 'System.Data.dataset' and Boolean"..[code]
View 2 RepliesIn the project�s btnReadNumber click event handler, replace the code in the try section of the try/catch block � the two if statements and the unconditionally executed code � with one if-else statement that performs the same tasks. Use the And operator to write the if-statement�s condition.What I don't understand is how am I supposed to use the 'And' operator so that when I insert a number between 32-16384 in the text box it'll allow it to go through and at the same time not allow any numbers lower than 32(lower_bound) and higher than 16384(upper_bound) to go through.I've use the 'Or' operator and that was simple, but with 'And' I'm not understanding it.Remember it has to be with the 'AND' operator. I bold the area where my problem is at. It's obviously not the right answer, but that's where I was stumped.
Dim sum As Integer = 0
Const upper_bound As Integer = 16384
Const lower_bound As Integer = 32
[code]....
Possible Duplicate: Is there a VB.NET equivalent for C#'s ?? operator? Is there an equivalent in VB.NET to C#'s ?? operator?
View 1 RepliesWhat is the equivalent operator in VB.Net for ^ (this is for C#)
View 6 RepliesSo Google's not a good choice for looking up examples for overloaded operators like "And" or "Or", because it tries to parse them as operators to the search query itself. MSDN also provides no examples of how to implement an overloaded And operator, so I'm not certain how to properly overload it for my project.Does anyone have an example of "And" at minimum? "Or" or "Xor" (or any others) would be a bonus. I'm not certain if I need to overload these operators in my objects just yet, as I'm still building them out and haven't planned beyond just yet. But having examples around that might get indexed by Google will probably help save the sanity of a lot of people...
View 2 RepliesDim x As Integer = 1.8 1
Error:
Option Strict On disallows implicit
conversions from 'Double' to 'Long'
What Long??
EDIT:
Apparently Visual Basic attempts to convert any floating-point numeric expression to Long. OK, this part is clear.
Now, I can use the
CType((Math.Round(myResultingSingle)), Integer)
but what for MSDN tells that operator supports all the types if in reality it supports only Long as expression1 ?!...