VBA : How to define a large set of string variables? - vba

I am trying (in VBA) to define a large number of string variables. The brute force would be :
Dim Port1 as String
Dim Port2 as String
etc…
Unpleasant for say 100 variables. There must be a more intelligent solution.
I have tried :
Dim n As Integer
For n = 1 To 100
Dim "Port" & n as String
Next n
and variations of it without success.
I would greatly appreciate if someone could point me in the right direction or share an example.

Arrays do exactly this! See this example:
Dim Port(1 to 100) As String
Dim i As Long
Port(1) = "String"
For i = 2 to 100
Port(i) = "String " & i
Next i
It sets Port(1), the first array element to the word "String". Everything else Port(2) and on, contain "String 2", "String 3", etc. Up to Port(100).
I hope that helps!

Related

How does the Val() function in VB.NET work?

I have an assignment in VB.NET that I'm stuck with at the moment. Would love some help.
The question is this: You enter random characters into a textbox, for example 12ab3c4d5efgh, and at the click of a button, it must sort the characters in the textbox into 2 separate Labels, depending on whether or not the 'character' is a number or letter. So, continuing the example, Label1 must show '12345' and Label 2 must show 'abcdefgh'. I hope I made myself clear enough.
I was asked to use the Val() function but I really have no clue. Could someone please help? :D
This creates one string with the digits and one with the letters. Characters that are not digits or letters are ignored.
Dim chars As String = "12ab3c4d5efgh"
Dim nums As String = chars.Where(Function(c) Char.IsDigit(c)).ToArray
Dim lets As String = chars.Where(Function(c) Char.IsLetter(c)).ToArray
If you have to use Val() something like this would do. But be careful: Val("0") also returns 0.
Dim numbers As String = String.Empty
Dim letters As String = String.Empty
Dim sourceString As String = "12ab3c4d50efgh"
For Each c As Char In sourceString
If Val(c) = 0 And c <> "0" Then letters &= c Else numbers &= c
Next
Console.WriteLine("Numbers: " & numbers)
Console.WriteLine("Letters: " & letters)
Console.ReadKey()

for loop : string & number without keep adding &

I'm learning for loop and I cannot get this problem fixed.
The problems are in the following codes.
dim rt as integer = 2
dim i As Integer = 0
dim currentpg as string = "http://homepg.com/"
For i = 0 To rt
currentpg = currentpg & "?pg=" & i
messagebox.show(currentpg)
next
'I hoped to get the following results
http://homepg.com/?pg=0
http://homepg.com/?pg=1
http://homepg.com/?pg=2
'but instead I'm getting this
http://homepg.com/?pg=0
http://homepg.com/?pg=0?pg=0
http://homepg.com/?pg=0?pg=0?pg=0
Please help me
Thank you.
You probably need something like this:
Dim basepg as string = "http://homepg.com/"
For i = 0 To rt
Dim currentpg As String = basepg & "?pg=" & i
messagebox.show(currentpg)
Next
Although a proper approach would be to accumulate results into a List(Of String), and then display in a messagebox once (or a textbox/file, if too many results). You don't want to bug user for every URL (what if there are 100 of them?). They would get tired of clicking OK.
First of all, you went wrong while copying the output of the buggy code. Here is the real one.
http://homepg.com/?pg=0
http://homepg.com/?pg=0?pg=1
http://homepg.com/?pg=0?pg=1?pg=2
It does not work because currentpg should be a constant but it is changed on each iteration.
Do not set, just get.
MessageBox.Show(currentpg & "?pg=" & i)
Or you can use another variable to make it more readable.
Dim newpg As String = currentpg & "?pg=" & i
MessageBox.Show(newpg)
Also, your code is inefficient. I suggest you to change it like this.
Dim iterations As Integer = 2
Dim prefix As String = "http://homepg.com/?pg="
For index As Integer = 0 To iterations
MessageBox.Show(prefix & index)
Next

VB.net incremented number concatenate with texbox value

I'm learning vb.net. I'm trying to create an incremental number that starts at 00000 and concatenate that number with a value from a textbox (eg. JH00001), then insert it into the database.
Please can someone kindly help me with this as I'm totaly new to vb.net.
Thank you all for your assistance in advance. And I'm sorry for my bad English.
Dim number as Integer = 1
Dim text as String = textbox1.text &= number.toString().padLeft(5, "0"c)
Use D5 precision specifier to indicate that the number should be at least 5 digits including leading zeros:
Dim valueFromTextBox As String = "JH"
Dim value As String = ""
For i = 0 To 99
value = valueFromTextBox & i.ToString("D5")
'Insert value to database
Next
Check MSDN for more formatting methods
A for loop should be what you need:
Something like:
Dim text As String = textbox1.text
Dim DBtext As String
For value As Integer = 0 To 5
DBtext = text & value.ToString()
'Insert anything else you need to do. Such as insert into DB.
Next
Just replace the 5 with however many times you need it to run.
I personally prefer using String.Format ...
For i = 0 to 1e6-1
Dim FormattedString = String.Format("{0}{1:00000}", Textbox1.Text, i)
Next

WWBasic + SPSS, script to rename value labels

before I start I want to point out that I tagged this question as VBA because I can't actually make a new tag for Winwrap and I've been told that Winwrap is pretty much the same as VBA.
I'm working on SPSS V19.0 and I'm trying to make a code that will help me identify and assign value labels to all values that don't have a label in the specified variable (or all variables).
The pseudo code below is for the version where it's a single variable (perhaps inputted by a text box or maybe sent via a custom dialogue in the SPSS Stats program (call the .sbs file from the syntax giving it the variable name).
Here is the Pseudo Code:
Sub Main(variable As String)
On Error GoTo bye
'Variable Declaration:
Dim i As Integer, intCount As Integer
Dim strValName As String, strVar As String, strCom As String
Dim varLabels As Variant 'This should be an array of all the value labels in the selected record
Dim objSpssApp As 'No idea what to put here, but I want to select the spss main window.
'Original Idea was to use two loops
'The first loop would fill an array with the value lables and use the index as the value and
'The second loop would check to see which values already had labels and then
'Would ask the user for a value label to apply to each value that didn't.
'loop 1
'For i = 0 To -1
'current = GetObject(variable.valuelist(i)) 'would use this to get the value
'Set varLabels(i) = current
'Next
'Loop for each number in the Value list.
strValName = InputBox("Please specify the variable.")
'Loop for each number in the Value list.
For i = 0 To varLabels-1
If IsEmpty (varLabels(i)) Then
'Find value and ask for the current value label
strVar = InputBox("Please insert Label for value "; varLabels(i);" :","Insert Value Label")
'Apply the response to the required number
strCom = "ADD VALUE LABELS " & strVar & Chr$(39) & intCount & Chr$(39) & Chr$(39) & strValName & Chr$(39) &" ."
'Then the piece of code to execute the Syntax
objSpssApp.ExecuteCommands(strCom, False)
End If
'intCount = intCount + 1 'increase the count so that it shows the correct number
'it's out of the loop so that even filled value labels are counted
'Perhaps this method would be better?
Next
Bye:
End Sub
This is in no way functioning code, it's just basically pseudo code for the process that I want to achieve I'm just looking for some help on it, if you could that would be magic.
Many thanks in advance
Mav
Winwrap and VBA are almost identical with differences that you can find in this post:
http://www.winwrap.com/web/basic/reference/?p=doc_tn0143_technote.htm
I haven't used winwrap, but I'll try to answer with my knowledge from VBA.
Dim varLabels As Variant
You can make an array out of this by saying for example
dim varLabels() as variant 'Dynamically declared array
dim varLabels(10) as variant 'Statically declared array
dim varLabels(1 to 10) as variant 'Array starting from 1 - which I mostly use
dim varLabels(1 to 10, 1 to 3) 'Multidimensional array
Dim objSpssApp As ?
"In theory", you can leave this as a variant type or even do
Dim objSpssApp
Without further declaration, which is basically the same - and it will work because a variant can be anything and will not generate an error. It is good custom though to declare you objects according to an explicit datatype in because the variant type is expensive in terms of memory. You should actually find out about the objects class name, but I cannot give you this. I guess that you should do something like:
set objSpssApp = new <Spss Window>
set objSpssApp = nothing 'In the end to release the object
Code:
'loop 1
For i = 0 To -1
current = GetObject(variable.valuelist(i)) 'would use this to get the value
Set varLabels(i) = current
Next
I don't exactly know why you want to count from 0 to -1 but perhaps it is irrelevant.
To fill an array, you can just do: varLabels(i) = i
The SET statement is used to set objects and you don't need to create an object to create an array. Also note that you did not declare half of the variables used here.
Code:
strVar = InputBox("Please insert Label for value "; varLabels(i);" :","Insert Value Label")
Note that the concatenation operator syntax is &.
This appears to be the same in WinWrap:
http://www.winwrap.com/web/basic/language/?p=doc_operators_oper.htm
But you know this, since you use it in your code.
Code:
'intCount = intCount + 1 'increase the count so that it shows the correct number
'it's out of the loop so that even filled value labels are counted
'Perhaps this method would be better?
I'm not sure if I understand this question, but in theory all loops are valid in any situation, it depends on your preference. For ... Next, Do ... Loop, While ... Wend, in the end they all do basically the same thing. intCount = intCount + 1 seems valid when using it in a loop.
Using Next (for ... next)
When using a counter, always use Next iCounter because it increments the counter.
I hope this reply may be of some use to you!

Display first and last half of any string entered into textbox

I want to display the first and last characters of any given string entered into a textbox. The strings can be of any length as the user wants (as long as it is one word) I would like to be able to do something like this... "william = will and iam" or "Celtic = Cel and tic"
I understand I would have to split or divide the string. How would I go about doing this? Any help is appreciated, thanks.
EDIT:
Thanks for your help once again guys, this is how the code ended up!
Dim strInput = txtString.Text
Dim halflength = strInput.Length / 2
Dim firsthalf = strInput.Substring(0, halflength)
Dim secondhalf = strInput.Substring(halflength)
Dim strResults = firsthalf
Dim secondResult = secondhalf
MessageBox.Show(firsthalf)
MessageBox.Show(secondhalf)
MessageBox.Show("First half of string contains... " & " " & strResults.Length.ToString & " characters", "Character Count")
MessageBox.Show("Second half of string contains... " & " " & secondResult.Length.ToString & " characters", "Character Count")
EDIT:
Also meant to mention my current incorrect code.
Dim strInput As String
Dim strLength As String
Dim strResults As String
strInput = txtString.Text
strLength = strInput.Length / 2
strResults = txtString.Text
MessageBox.Show(strInput.Length.ToString, "Length of characters")
MessageBox.Show(strLength.ToString)
MessageBox.Show(strResults.Substring(0, 3))
String.Substring and String.Length should give you everything you need to get started on this.
Seeing your existing code will make this easier. Let's walk through what we have now.
Let's assume we have just a plain, simple string like this instead of a textbox for the sake of making things easier:
Dim txtString = "Hello World"
Now, in order to split the length of the string in half; we need to get the length. The `Length property will give is that, and then divide it by two.
Dim halfLength = txtString.Length \ 2
This will perform integer division; so any remaining decimal is truncated.
Now we know where the middle of the string is. We can now use String.Substring to carve out a peice of the string by index. Substring takes two parameters, the index where to start the string, and number of characters to take. There is a second overload that takes the index to start at and consumes till the end of the string. Indexes are zero based. So for example, if we wanted to start at the beginning of the string, we'd use zero. If we wanted to skip the first character, we'd use one.
For the first half of the string, we don't want to skip any characters, so we'll use zero. The number of characters we want is half length of the string, so we pass in halfLength:
Dim firstHalf = txtString.Substring(0, halfLength)
For the second half, we want to start in the middle of the string, and consume characters till the end, so we'll use the other overload:
Dim secondHalf = txtString.Substring(halfLength)
You now have your string split in half.
The final result looks like this:
Dim txtString = "Hello World"
Dim halfLength = txtString.Length \ 2
Dim firstHalf = txtString.Substring(0, halfLength)
Dim secondHalf = txtString.Substring(halfLength)
Assuming the rules are "each side is half the length with the left side taking precedence", you would use Substring and some simple division:
Dim str As String = "william"
Dim part1 As String = str.Substring(0, CInt(Math.Ceiling(str.Length / 2.0#)))
Dim part2 As String = str.Substring(part1.Length)
part1 & " and " & part2 'will and iam
Here's a demo.
My code displays first half and last half of any number of characters entered.
Declare Variable
Dim strResults As String
Fetch text from textbox
strResults = Textbox1.Text
Display the first half of the text
MessageBox.Show(strResults.Substring(0, strResults.Length / 2), "First Half Characters")
Display the last half of the text
MessageBox.Show(strResults.Substring(strResults.Length / 2), "Last Half Characters")
Full code:
Dim strResults As String
strResults = Textbox1.Text
MessageBox.Show(strResults.Substring(0, strResults.Length / 2), "First Half Characters")
MessageBox.Show(strResults.Substring(strResults.Length / 2), "Last Half Characters")