I want to create a multi-dimensional array where I assign all the values at once instead of going through all the array coordinate values one by one. I believe this is called setting 'array literals'. Anyway, all my variables are string values. The code below doesn't give me a syntax error but when I step through I'm getting a "Compile error: Can't assign to array" message on pkg= line. How do I make this work?
Sub test_array2()
Dim pkg(2, 2) As String
pkg = [{"PRetail","Retail Packaged"};{"PFoodservice","Foodservice
Packaged"}]
Debug.Print pkg(1, 1)
End Sub
You cannot assign directly to an array like that, so you need to use a variant:
Sub test_array2()
Dim pkg As Variant
pkg = [{"PRetail","Retail Packaged";"PFoodservice","FoodservicePackaged "}]
Debug.Print pkg(1, 1)
End Sub
Related
I am learning about declaring arrays. It works when I declare it by giving an upper limit using following code:
Dim arrayA(5) as String
I check it by assigning a random value:
arrayA(0) = 1
MsgBox arrayA(0)
MsgBox responds by giving a value of 1.
However, my actual intention is to create a dynamic array that I defined as below:
Dim arrayA() as String
I test it in the same way
arrayA(0) = 1
MsgBox arrayA(0)
But this time it does not work and MsgBox pops up empty. Would someone tell me if I need to load some libraries to work with dynamic array?
Arrays in VBA need to be initialized before they are used.
You can initialize an array with a Redim statement:
Dim arrayA() as String
Dim i As Integer
i = 0
Redim ArrayA (0 To i)
arrayA(0) = "1" 'String
MsgBox arrayA(0)
Alternatively, there are functions that return an initialized array. In that case, Redim is not needed as the initialization happens in the external function. You do need to make sure you match type with the array being returned, though, and the overhead is the same or more.
Dim arrayA() as Variant
arrayA = Array(1)
MsgBox arrayA(0)
You can declare an array without a limit, but must redim the array to the desired limit prior to using it:
Dim myArray() As Long
Redim myArray(0)
myArray(0) = 0 'etc...
So, you cannot use a "dynamic" array in VBA like this.
The best reference I've ever known for arrays (and much other VB/A related information), comes from the late Chip Pearson: http://www.cpearson.com/Excel/VBAArrays.htm
VBA Beginner here.
I am trying to pass an array of strings from a subroutine to a function which will then modify each string in the array. However I get the "Type:array or user-defined type expected" error message.
I have tried redefining different data types for the array so it is aligned with the data type entered in the function but to no avail.
Hope you can help! THank you so much!
Below is the dummy code:
Sub text()
Dim haha() As Variant
haha = Array("Tom", "Mary", "Adam")
testing (haha())
MsgBox Join(haha, " ")
End Sub
Function testing(ByRef check() As String) As String()
Dim track As Long
For track = LBound(check) To UBound(check)
check(track) = check(track) & " OMG"
Next
End Function
In orignial code, a string is not the same variant (I believe they both would need to be variant? someone can verify), you dont need the brackets after testing, only need brackets if you are setting to another value e.g.
haha2 = testing(haha())
Below code should be ok
Sub text()
Dim haha()
haha = Array("Tom", "Mary", "Adam")
testing haha()
MsgBox Join(haha, " ")
End Sub
Function testing(ByRef check()) As String
Dim track As Long
For track = LBound(check) To UBound(check)
check(track) = check(track) & " OMG"
Next
End Function
You have a few errors in your code:
There are two ways of invoking methods:
1) with Call keyword - in this case you must give all the parameters in brackets:
Call testing(haha)
2) without Call keyword - in this case you just give your parameters after the name of function:
testing haha
In your code you combined both of them and this is syntax error.
If you pass an array as a parameter to function you don't need to put brackets like that: testing (haha()).
The proper syntax is:
testing(haha)
Function testing requires as a parameter an array of String type, you cannot pass object of other type instead since it causes compile error Type mismatch. Currently you are trying to pass variable haha which is of Variant type.
You can change the type of haha variable to array of strings (to avoid the error described above):
Dim haha() As String
However, in this case you cannot assign the value of function Array to it, since the result of this function is of Variant type.
You would have to replace this code:
haha = Array("Tom", "Mary", "Adam")
with this:
ReDim haha(1 To 3)
haha(1) = "Tom"
haha(2) = "Mary"
haha(3) = "Adam"
A couple of suggestions to improve your code:
Dim haha() As String
You define the type of the entry in the array, not the array itself. Use the way mentioned by mielk to fill the array.
Function Testing(byref check as variant) As String
This will avoid problems with undefined variables. Not clear why you feel that the function should return a string though. Maybe even convert to a Sub instead.
Got a simple question. The Array() function in VBA does return a two dimensional array? I'm trying to create a one dimensional array with this function and use it in the filter() function but it says "type mismatch". And if that's the case, how can I force Array() to create a one dimensional array?
Sub tester()
Dim xWorkb As Excel.Workbook
Dim xFiles_target() As String
Dim file_path As String
xFiles_target = Array("Bella.xls", "Fizz.xls", "Milo.xls")
file_path = Dir("C:\Users\hans\Desktop\")
Do While Len(file_path) > 0
Debug.Print file_path
If UBound(Filter(xFiles_target, file_path)) >= 0 Then
Debug.Print "found " & file_path
End If
file_path = Dir
Loop
End Sub
Array function does create a 1D Array. However the function requires the variable you are assigning to, to be of Variant type. It cannot be String/Number.
Dim tmpArr() As String
tmpArr = Array("Hello", "World")
The above is likely to throw Type mismatch error. However,
Dim tmpArr()
tmpArr = Array("Hello", "World")
The above will take it as such. That is no error will be thrown but the tmpArray now has two elements to it.
The Split function will result in a String array. Although Variant type can take in String, a Number array cannot take in the Split function.
More information about this neatly organized here : http://patorjk.com/programming/tutorials/vbarrays.htm
Hope this helps.
I have interesting situation with passing two-dimensional array through functions.
Array is declared at form's level scope:
I try to rewrite a part of my code from VB6 where I have workable example.
Dim myArray(,) As Double
Then I get a sub where array is redimed and filled according to data, something like this, symbolic situation:
Public Sub mySub(ByVal myArray(,) As Double)
Dim temparray() As Double = {3, 5, 7, 9}
For a As Double = 0 temparray.length - 1
ReDim Preserve myarray(2, temparray(a))
Next a
myArray(1, 5) = 3.14
... etc...
End Sub
And finally, I would like to fill and read data in array from other sub:
mySub(myArray)
Debug.Print(myArray(1, 5))
And here I get error message:
Object reference not set to an instance of an object.
Data in mySub is filled properly but I can't see this data in calling sub.
What do I do wrong and how can I get this scenario working?
You can solve it by doing this:
Public Sub mySub(ByRef myArray(,) As Double)
'...
End Sub
You need to reference the variable in order to have the changes outside the Sub.
I have a Sub with an array of strings as parameter:
Private Sub des(ByVal array() As String)
Dim i As Integer
For i = 0 To UBound(array)
array(i) = "hy"
Next
End Sub
When I call the function inside my main function, the value of str changes even if the array is passed to the function ByVal:
Dim str() As String
str = {"11111", "22222", "33333", "44444", "5555", "66666"}
des(str)
I tried making a copy of the array in the Sub, but it still changes in the main function.
Private Sub des(ByVal array() As String)
Dim i As Integer
Dim array2() As String
array2 = array
For i = 0 To UBound(array)
array(i) = "hy"
Next
End Sub
I read on a site that you cannot pass arrays ByVal. Is this true? If so, how should I proceed?
Try this:
Dim i As Integer
Dim array2() As String
array2 = array.Clone()
For i = 0 To UBound(array2)
array2(i) = "hy"
Next
The key difference is the .Clone(), that actually makes a shallow copy of array, and changing the values in array2 will no longer affect your str value in the main code.
Arrays are reference types. That means that when you pass an Array to your function, what is passed is always a reference, not a copy of the array. The Array in your function refers to the same array object as the Array in your calling code.
The same thing happens when you do the assign (it is not a copy!) in your second example: all you've done is make yet another reference to the same object. That is why Boeckm's solution works -- the Clone() call does make a new array and assign it values which are copies of the values in the original array.
In Visual Basic .NET, regarding arrays as parameters, there are two important rules you have to be aware of:
Arrays themselves can be passed as ByVal and ByRef.
Arrays' elements can always be modified from the function or subroutine.
You already know that you can modify the elements of an array inside a subprocess (subroutine or function), no matter how that array is defined as parameter inside that subprocess.
So, given these two subroutines:
Private Sub desval(ByVal array() As String)
array = {}
End Sub
Private Sub desref(ByRef array() As String)
array = {}
End Sub
And this very simple auxiliary subroutine (here I'll use the Console):
Private Sub printArr(ByVal array() As String)
For Each str In array
Console.WriteLine(str)
Next
End Sub
you can do these simple tests:
Dim arr1() as String = {"abc", "xyz", "asdf"}
Console.WriteLine("Original array:")
printArr(arr1)
Console.WriteLine()
Console.WriteLine("After desval:")
desval(arr1)
printArr(arr1)
Console.WriteLine()
Console.WriteLine("After desref:")
desref(arr1)
printArr(arr1)
I read on a site that you cannot pass arrays ByVal. Is this true?
No, that is not true.
An array in the .NET framework is a reference type. When you create an array, an object of System.Array will be created and its reference is assigned to the reference variable.
When you call a des method, the reference of the array object will be passed. In des method, ByVal parameter is a reference parameter variable of type System.Array, and it receive a copy of reference of an array object.
MSDN article - Passing Arguments by Value and by Reference (Visual Basic)