Passing Arrays to Sub Routines and Functions
Simple code example:
Option Explicit Private Sub cmdGo_Click() Dim aFruit(9, 1) aFruit(0, 0) = 34 aFruit(0, 1) = "Apples" aFruit(1, 0) = 56 aFruit(1, 1) = "Oranges" aFruit(2, 0) = 4 aFruit(2, 1) = "Peaches" Call DoDisplayIt(aFruit) End Sub Private Sub DoDisplayIt(aFruit) Dim cnt As Integer txtOut.Text = "" For cnt = 0 To 2 txtOut.Text = txtOut.Text & vbCrLf & cnt & ". " & aFruit(cnt, 1) & " (in stock): " & aFruit(cnt, 0) Next cnt End Sub
Arrays are passed to procedures "By Value" by default in Visual BASIC. By Value means that the pointer is being passed, not the actual values. So if the Array value is modified in the procedure, it is also modified from the code after where the procedure is called. Visual Basic will not allow you to pass the value of an Array to a procedure "By Value."
Call RoutineA(varArray) Private Sub RoutineA(ByRef intArray() As Integer) Dim obj As Variant For Each obj In intArray Form1.txtOut.text = Form1.txtOut.text & vbCrLf & obj Next End Sub
pass an Array back to the calling procedure
Private Function ReturnArray() As Variant Dim MyArray(3) As Integer 'Declare a Static Integer Array of 4 elements MyArray(0) = 1 MyArray(1) = 2 MyArray(2) = 3 MyArray(3) = 4 ReturnArray = MyArray 'Pass the array back as a return value End Function
Accept an Array as an argument.
Private Sub cmdReturnArray_Click() Dim retval As Variant Dim obj retval = ReturnArray 'Assign the return value to a Variant Variable For Each obj In retval Form1.Print obj Next End Sub
Byte Arrays
Convert String to ANSI Byte Array
Use the StrConv function with "vbFromUnicode" to convert a Visual Basic string to a byte array of ANSI characters.
Dim company As String Dim b() As Byte company = "CHILKAT SOFTWARE" b = StrConv(company,vbFromUnicode)
Convert Byte Array to String
Use the StrConv function with "vbUnicode" to convert a byte array of ANSI characters to a string.
Dim s As String Dim b(1 To 3) As Byte b(1) = Asc("A") b(2) = Asc("B") b(3) = Asc("C") s = StrConv(b, vbUnicode)