I just want to know, what exactly the difference between the functions CStr() and Str() and also the .ToString()? With the code provided below, what's the difference between the three?
[Code]...
I'm learning to use this program and I'm a few weeks into learning it and I'm understanding most of it fine, but I just cannot get a grasp on when to use CDbl, CInt, CStr etc. functions. Here's an example of a few lines of code I can't get a grasp of:
If IsNumeric(txtFirst.Text) And IsNumeric(txtSecond.Text) Then
txtSum.Text = CStr(CDbl(txtFirst.Text) + CDbl(txtSecond.Text))
This program is supposed to take 2 numbers that are inputted by the user and add them together. simple. I was playing around with it, and I took out the CDbl and CStr functions, and the 2 numbers that were supposed to be added together were only added side by side (ex. If I input 2 and 15 as my numbers it would spit out 215).
So I'm curious when to use these functions.
My first nagging question is, how come on the second line, it says CStr(CDbl(? Why would I need to convert to double, THEN to string? which is my understanding, unless I am reading this wrong.
Another question I have is, if I declare var1 as Dim var1 as Double I constantly see the next line as var1 = CDbl(txtbox.text) and so on. I don't understand why we need to convert to Double here, since when I declared the variable as a double, it should already be in a double form already, shouldn't it?
1. What's the difference between ToString and ToString()? (i do know that ToString method is to cast numeric values to string but don't know how to get it to work)
2. Why do i need XML comment feature? is it necessary?
When I am concatenating object values together to form a string in VB.NET, is there a difference in performance or a recommended best practice between using the & concat or the + concat with calls to .ToString() on each object?
Example (which is faster or best practice):
Dim result1 As String = 10 & "em"
Dim result2 As String = 10.ToString() + "em"
I'm not new to coding but fairly new to Visual Basic.Can someone tell me the difference between using the System.IO.Directory.Whatever and the Me.Computer.FileSystem.Whatever functions when it comes to file and folder manipulations?
View 1 Repliesgive me a good resource that explains the difference between a Private, Public, Shared Functions/Sub/Variables? I normally use Public for Subs/Functions inside of Modules I call from other parts of the program. But I'd like to get more of an understanding of how and when to use them. I want as little as impact to a system that is running my programs as possible, so i guess the key here is I'm trying to just get more proficient in my coding.
View 8 Repliesi have have a few questions about the syntax of the lan.:
1) What is the 'Get' statement and when do you use it?
2) Whats the difference between public, private, protected etc... when declaring functions and subs.
3) When would you use the overrides property?
I want to know what are classes , objects , a namespace , subroutines,functions,methods,properties and differemce betweem byval and byref in your words.
View 18 RepliesCStr in VB script throws error when NULL value is passed to it, whereas CStr in VB.NET ignores null value and doesn't throw error.
Is there any other function which does same function as CStr in VB script.
Try
Dim str As String
str = Nothing
'assuming above line will set str to null.
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What I am trying to do is have a class where the functions of the same name are both instance functions and shared functions.
Public Shared Function Get...(byval xx as xx)
and
Public Function Get...
The Public Function uses a Property xx created in the constructor, whereas the Shared Function has the parameters (byval xx as xx).
How can I get this to display in currency format. Righ now it's coming out with the right math but only carrying one decimal place and I get no dollar sign.[code]
View 2 Replies1) Is it possible to access the Excel mathematical functions without actually opening Excel?
I was thinking of through a DLL WinAPI call or maybe a delegate function or smaller program?
2) Does anyone know of a MS link or area that gives instruction on "how to" use every function of every Windows DLL at all?
Or for all those that Microsoft have chosen to document online at least.
While converting types, I have found myself using both VB functions and BCL Convert.To* methods.
E.g.)
Cstr() vs. Convert.ToString()
CInt() vs. Convert.ToInt32()
CDbl() vs. Convert.ToInt64()
etc...
Are there any subtle differences that should be noted?
Is there a way to see exactly what the functions are doing. What i mean is there a way to see the class? I know what it does, i just want to know the code.
For example the function: Membership.FindUsersByName()
I have no idea how to do this, but I want to create a [I dont know what it is called] to allow me to convert a class property to another type.The I could use the following w/ the new type:
Dim stringPhoneNo as String = "(111)111-1111" Dim typePhoneNo as PhoneNumber = stringPhoneNo.ToPhoneNumber()
When a custom class overrides the ToString() method, the C# IDE uses this function to display the class in the debug mode(tooltips, watcher etc) Does the VB.NET the same? I have impression that overriding ToString() method does change nothing. I mean, in the watcher I see Name myBusinessObjectInsnace Value {MyNamespace.myBusinessObjectInsnaceType}
View 4 RepliesIf you try to compile the query below in Visual Basic .NET, it fails. From x In {1, 2} Select x.ToString() The error given by the compiler is: Range variable name cannot match the name of a member of the 'Object' class. There is nothing wrong with the equivalent C# query, though: from x in new[]{1, 2} select x.ToString()
This does not happen with the ToString overload that takes a format (it is a member of Int32, not Object). It does happen with other members of Object, as long as they don't take an argument: with GetType and GetHashCode it fails; with Equals(object) it compiles.
My problem is that I'm trying to parse a String to a System.Drawing.Color. Im trying to set up a simple notepad, here's part of my code:
Private Sub ToolStripMenuItem6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Colorfuente2.Click
Try
Dim cdlg As New ColorDialog[code].....
I've googled like crazy and tried MSDN but I can't get a clear answer what to use ToString for.
View 11 RepliesI just converted a VB.net solution into C# solution. But lots of variables have been coverted like:
string var1 = (string)1;
string var2 = (string)intVar; //intVar is a int value
I just want to convert all (string)XXXX to XXXX.ToString() by using some Regular expressions or some other replace methods.
I know that i use a "c" for American Currency is there a ToString value used for Mexican Pesos?
View 2 RepliesMany times i was not getting correct output,then i put .tostring() at the end then it gave good output.so basically why do v need this?also Convert.ToInt32(cmd.ExecuteScalar()) why convert to int32?
View 1 RepliesConverting an object .tostring() removes the leading zeros. The object is not a fixed length, so I can't do object.tostring("0000000") where the number of zeros represents the fixed length.
An example object value is "0357" when I convert that object .tostring it becomes "357".
Is there a method for keeping the leading zeros where the length is not known?
Possible Duplicate: C#: why does the string type have a .ToString() method?Why is there a ToString method exist in String class (VB.NET)?
String.ToString()
Will it be a overhead if it is used like
TextBox.Text.ToString()
If we make a class and implement tostring, should we support some interface?
View 5 Replieswhy is it that in the properties i have set version to 1.2 as a decimal but when i call
MsgBox(My.Settings.version.ToString)
i get shown "1"
VB.NET 2008. How could I make a new line inside the ToString() Function that VB already have. How to do like a .WriteLine() but inside the ToString() function. In my case, this inside of a class of course. I don't know if you get me. All I want to do is to show a fraction in the normal way not using the slash(/). Showing the numerator on top of a line, and below it the denominator. This inside the VB pre-made ToString() function.
This is what I've tried;
Public Overrides Function ToString() As String
Return Me.numerator & "/" & Me.denominator
End Function
Output example: 2/3
But this is not what I want.
I've been programming in vb.net a lot for the last 9 weeks and I have just come across a lot of double functionalities (hope I used the right word for that).For instance, you can use CInt, CType, Directcast or Convert to turn something into a integer. (Directcast doesn't really belong in that line but whatever).
With calling methods you can do DoWork() or call DoWork()With returning values in functions you can do DoWork() = 3 or return 3 Why is this? Is it just to make the transition frm vb6 to vb.net easier? Or about giving the programmar a lot of options. I must admit I don't really like to have that choice, I am always in doubt whether I am using the right method .
Is the default format of ToString dependent on anything server related? Here's the issue: I'm testing and have tested an application on my local machine and ToString(), by default, is returning in a format of "MM/dd/yyyy hh:mm:ss tt", however on our server it appears to be returning as "dd/MM/yyyy hh:mm:ss tt" which the consuming application is not expecting and causing errors.
Dim uvExpireDate = DateTime.Now.AddMinutes(1)
Dim token = String.Format(fmtString, uvExpireDate.ToUniversalTime().ToString(), [various other params])
I have a custom business object which overloads the .ToString() function. It also implements IFormattable.ToString, so I can define my own custom formats.This approach seems to work everywhere in my app, except .rdlc reports. For example, I have a text field on a report with the following expression:
=Fields!MyField.Value.ToString("lr")
"lr" is a custom format I have created. When running the report I always get #Error as the output. I've placed breakpoints in my .ToString function and stepped through the code as the report is running, and I know the function is returning the correct value, but the report just doesn't seem to be capable of receiving and displaying it.