Array Control

[purplegerbil]

Hi,

I have an array that contains 5 elements:

i.e.
a(0) = "A"
a(1) = "B"
a(2) = "C"
a(3) = "D"
a(4) = "E"

What I want to be able to do is remove the first element then add information to the end.

e.g.
a(0) = "B"
a(1) = "C"
a(2) = "D"
a(3) = "E"
a(4) = "F" ; <- New

a(0) = "C"
a(1) = "D"
a(2) = "E"
a(3) = "F"
a(4) = "G" ; <- New

etc.....

Is there an easy way to remove the first element in an array?

Thanks for any help.
pG

[bushman_222]

why do you want to remove the first element and then add one to the end.

maybe it would be better to keep the 5 elements and move the data inside them?

so
temp = A(0)
A(0) = A(1)
A(1) = A(2)
A(2) = A(3)
A(3) = A(4)
A(4) = temp

[Jishnu]

why do you want to remove the first element and then add one to the end.

maybe it would be better to keep the 5 elements and move the data inside them?

so
temp = A(0)
A(0) = A(1)
A(1) = A(2)
A(2) = A(3)
A(3) = A(4)
A(4) = temp

The OP wants to add new elements too. Your code doesn't support that.

@purplegerbil

There are many inbuilt functions for string manipulations in VB6. Go to Object Browser and check out the functions in the String class.

[purplegerbil]

Thanks for your reply.

This is what I have gone with:

Option Explicit

Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As Long)

Private Sub Form_Load()
    Dim strTest() As String
    ' some initial data
    ReDim strTest(4)
    strTest(0) = "A"
    strTest(1) = "B"
    strTest(2) = "C"
    strTest(3) = "D"
    strTest(4) = "E"
    
    ' remove the first item
    strTest(0) = vbNullString
    ' copy remaining items one step to the beginning
    CopyMemory ByVal VarPtr(strTest(0)), ByVal VarPtr(strTest(1)), UBound(strTest) * 4&
    ' mark last item to be vbNullString to avoid having two string variables pointing to the same string data
    ' (it would be crashingly dangerous to leave both to point to the same data)
    CopyMemory ByVal VarPtr(strTest(UBound(strTest))), 0&, 4&
    
    ' now add the new item
    strTest(4) = "F"
    ' show what we have
    Debug.Print Join(strTest, " + ")
End Sub

pG

[Jishnu]

I thought that you wanted the value of the last element to be assigned dynamically. But, this is also fine. Please do mark the thread as solved if it is so.