Testing String Value Of Nothing Is Equivalent To String.Empty

Feb 24, 2010

I have a nullable database field of type varchar. I am writing a unit test for a service method that retrieves the value of this field. The service method uses a custom DAL that returns a value of String.Empty if the database field is Null (this is desired behaviour).

[Code]...

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Nothing Equals String.Empty, Null Does Not Equal String.Empty?

Jun 28, 2010

This must've have been asked before but I couldn't locate it. In a mixed code project (VB and C#) we were debugging some old Visual Basic code where a statement as follows could be found:

If Request.Params("xxx") <> "" Then
'do something

I considered this a bug as Request.Params could be null, in which case the statement would've become false which wasn't the idea. So I thought. I just found out, -- probably for the tenth time and I will keep forgetting -- that the following two statements are not equal, while Nothing in VB should be equal to null in C# (thought I):

if(String.Empty == null) // always false
If String.Empty = Nothing Then ' always true

Should I dismiss this as a typical Microsoft backward compatibility effort, or should I consider this a huge error in the VB.NET compiler? Does anybody know the Microsoftean opinion on this oddity?

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Arrays - If Not String.Empty Ignoring Empty String

Aug 11, 2010

I have a array of strings and I am looping through them, but the string might be empty so I am trying this:

[Code]...

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An Equivalent To SortedList(of String, String) That Accepts Non-unique Keys?

Apr 16, 2012

What I need is to be able to put in a SortedList a combination of two fields that are non-unique, but the pair is (like database composite keys).More precisly, i have my list, and i want to be able to do this with it

Dim myList = New Generic.SortedList(Of String, String)
myList.add("aaa","aaa")
myList.add("aaa","bbb")

[code].....

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Why STRING Does Not Have A Parameterless Constructor To Create An Empty String

Feb 4, 2012

I was trying to call a method using Reflection on a method that has a STRING parameter.However a STRING does not have a parameterless constructor.So instead of something like.>>

Option Strict On
Option Explicit On
Option Infer Off
Public Class Form1

[code].....

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[2008] Finding The First Empty String In A String Array?

Mar 2, 2009

i have a string array that i want to output to a text file. the array size is 10000. i fill the array starting from 0 with some strings. at the end, i only want to show the array from index 256 to the last array that is not empty (for eg. if the array is filled with data from 0 to 2000, i only want the text file to show the data from 256 to 2000 and ignore the remaining strings). Is there any function to do this?t i use is shown below

Dim myArray(10000) as string
Dim strArray As New System.IO.StreamWriter("c:List.txt")
strArray.WriteLine("{0,10}{1,30}", "Index", "Symbol")

[code].....

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Finding The First Empty String In String Array?

Mar 2, 2009

i have a string array that i want to output to a text file. the array size is 10000. i fill the array starting from 0 with some strings. at the end, i only want to show the array from index 256 to the last array that is not empty (for eg. if the array is filled with data from 0 to 2000, i only want the text file to show the data from 256 to 2000 and ignore the remaining strings). Is there any function to do this? i am using visual basic express 2008. The code that i use is shown below

[Code]...

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When String Variable Was Empty String First One Returns 'nothing'

Oct 2, 2009

just found out that replace(string does not do the same as string.replace when my string variable was an empty str the first one returns "nothing" and the second returns an empty string (as expected).just sloppy coding anyhow, it was a function that was converted from classic asp and never rewritten properly. [code]

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Compact Framework - Testing If A String Can Be Cast As A Integer?

Nov 3, 2009

Is there a better way of testing if a string can be converted to an integer other than something like the following?

Public Function IsInt(ByVal value As Object) As Boolean
Try
Dim temp As Integer = CInt(value)

[code].....

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Asp.net - Swapping A Connection String To Access A Test Database For Unit Testing?

Jun 22, 2009

I've set up a test database to begin unit-testing an app that I've recently been added to. It is a 3-tier design (presentation layer, BOL and DAL) and this is my first time writing unit tests. I've decided to start at the BOL and I figure the best way is to swap out the ConnectionString (which has been passed along as a Shared String) with one that points to my new test database. However, I don't wish to change any production code. I simply wish to somehow redirect the app to the test database during unit tests.

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Unit Testing - Use Assert.AreEqual To Evaluate If String Is Greater Than A Certain Length

Feb 1, 2011

I'm wondering how to evaluate an expression using the assert object. The idea is to check if a string is longer then what is minimally acceptable. For example, Assert.AreEqual(stringName.length, >5). I know this method doesn't work but the concept is what I'm trying to get across. Is there a way to test this?

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VS 2008 Testing If An RTF File Is Empty?

Aug 29, 2010

When listbox is added to by the user a number of empty RTF files are created and saved with a string variable SavePath1,SavePath2 and SavePath3. The user can then add date to 3RichText boxes and save the data. The data can then be cleared from the RichText boxes, anotheraddition to the listbox and fill the RTB and save. I need to trap the RTBs being filled and the clear button being pressed before the data is saved. To do this I need to test for empty files and tell the user the data has not yet been saved.

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VS 2010 Testing For Empty EventArgs?

May 1, 2010

I'm encountering a scenario where I need to see if e is "Empty" before I execute code (don't execute if it's Empty).In a routine similar to the following, I can see while debugging the code that "e" is empty, but I can't figure out how to test it in the

Private Sub RadioClick(ByVal sender As RadioButton, _
ByVal e As System.EventArgs) _
Handles Radio1.Click, Radio2.Click, Radio3.Click, Radio4.Click

[code]....

For some reason, I'm encountering situations where this event is being raised by clicking anywhere on the form. However, when this happens, e is Empty. If I can test for that, then my bug will go away, but I haven't been able to figure out the syntax.

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VS 2010 Testing For Empty Fields?

Mar 14, 2011

I used to run into problems with this in VB6, too...

If Not ds_Students.Tables(0).Rows(0).Item("ClassDay2").IsNullOrEmpty Then
txtClassDay2.Text = ds_Students.Tables(0).Rows(0).Item("ClassDay2")
End If
This produces "Public member 'IsNullOrEmpty' on type 'DBNull' not found."

And is there a different test for fields of different data types?

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Get Type Object From Its String Equivalent?

Nov 3, 2009

for Types, we could call toString and convert that into a String, but i would like to do the reverse i.e getting a Type object from its string.

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What Is The Equivalent To Vb6 String(number - Character)

Feb 16, 2009

what is the vb.net equivalent to vb6 String(number,character?

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C# - .Net Equivalent Of The Old Vb Left(string, Length) Function?

May 9, 2009

As a non .net programmer I'm looking for the .net equivalent of the old vb function left(string, length). It was lazy in that it worked for any length string. As expected, left("foobar", 3) = "foo" while, most helpfully, left("f", 3) = "f".

In .net string.Substring(index, length) throws exceptions for everything out of range. In Java I always had the Apache-Commons lang.StringUtils handy. In Google I don't get very far searching for string functions.

Edit:@Noldorin - My first encounter, although it took me several seconds to do the same in c#:

[Code]...

Note the static class and method as well as the this keyword. Yes, they are as simple to invoke as "foobar".Left(3). See also c# extensions on msdn.

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Add Empty String To RadComboBox?

Jun 8, 2009

I have a webpage that has a Telerik RadComboBox on the page. One of the properties of this ComboBox is EmptyMessage, which fills the combobox with a message when an item is not selected. I am binding my combobox to a datasource at runtime and for some reason, it wipes this EmptyMessage away. Is there a way to keep my data items in tact and have the empty message there too?

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Appropriate Way To Set StringBuilder To An Empty String?

May 19, 2010

I'm using VB's StringBuilder, and I was curious what is considered "best practice" for emptying the builder/setting it to a new string. Would it be something like this:[code]or is there a "Better" way?

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C# - The Benefits Of Using String.Empty?

Sep 16, 2010

Possible Duplicate: In C#, should I use string.Empty or String.Empty or "" ? I just don't understand the benefits of using String.Empty over "". Aside it being strongly typed its longer.

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Convert 0.0 To Empty String?

Apr 30, 2012

I am storing value in Double. If that value is 0.0, I dont want to display anything.

means,

If Value = 14.0, I want to display Value = 14.0
If value = 0.0, I want to display Value =

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Nothing = String.Empty (Why Are These Equal?)

Apr 13, 2010

Why does the first if statement evaluate to true? I know if I use "is" instead of "=" then it won't evaluate to true. If I replace String.Empty with "Foo" it doesn't evaluate to true. Both String.Empty and "Foo" have the same type of String, so why does one evaluate to true and the other doesn't?

//this evaluates to true
If Nothing = String.Empty Then

[CODE]...

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Should This Really Return An Empty String()?

Nov 26, 2010

I have an attribute class:

[code]...

With that said, shall the Private Property Attributes() As String() not return the values of DirectoryAttribute placed over the interfaces properties as well, since I specify True in the inheritance parameter of the Type.GetCustomAttributes method?

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Convert String To Proper Case (strConv Equivalent)?

Jul 30, 2007

To convert a string to proper case what's .NET equivalent of Visual Basic strConv Function?

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Assign Empty String To Property With Value Of Nothing

Jan 5, 2011

In my EF4 EntityModel I have an entity named Users. Users have the common UserName and Password string fields. If I do something like this

Dim u as new USERS
U.UserName = String.Empty
Then U.UserName are still Nothing.

But if I Do Something like this
Dim u as new USERS
u.UserName = "A"
u.UserName = String.Empty
Then U.UserName take String.Empty as value without problem.

The reason is the way that EF4 generate the UserName Property
Public Property UserName() As Global.System.String
Get
Return _UserName
End Get
[Code] .....

I do not want to make two assignations every time I want to set string.empty to a property with a nothing value, and I do not want to remember that I must do it in this way everytime, because I'm pretty sure that I will forget it and then I will introduce bugs in the code. I just want to assign the empty.string value to a property and the property take "" as value.

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Check If A String Collection Is Empty?

Aug 19, 2009

How can i check if a string collection is empty? I tried

VB.NET
My.Settings.IPBank.Count = 0
But it said

Quote:

Object reference not set to an instance of an object.

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Converting A Decimal To An Empty String

Oct 31, 2011

I'm sure this is simple to do but I'm struggling to get this work, I've tried using convert.tostring, decimal.tostring, ctype(object, type) and cstr(object) but without success. I guess I'm trying to change the decial object to a string object and then assign it a value of empty string but always get type mismatch error.[code]

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Create An Empty String That Is A Certain Length?

Jan 31, 2011

How can I create an empty string that is a certain length?

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Parameter 'addresses' Cannot Be An Empty String

Jul 27, 2010

In my program i have it send an email and it send the email but after it sends i get this error "The parameter 'addresses' cannot be an empty string. Parameter name: addresses". I don't know why.

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String Empty Error Validation

Apr 26, 2011

To make it clear this IS homework, however this is also a method of research. i only ask when i get in binds i can not find answers to in other forums . There are so many i could spend more time[code]...

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