Dynamic Array Class

<%
    Class DynamicArray
        private data
 
        ' Constructor
        private sub Class_Initialize()
            data = Array()
        end sub
 
        ' Returns the number of items in the array.
        public property get Count
            if ubound(data) > 0 then
                Count = ubound(data) + 1
            else
                Count = 0
            end if
        end property
 
        ' Return the item at the specified index of the array.
        public property get Item(position)
            'Make sure the end developer is not requesting an "out of bounds" array element.
            if position < lbound(data) or position > ubound(data) then
                'Invalid range.
                exit property
            end if
 
            Item = data(position)
        end property
 
        ' Return the array itself.
        public property get Items()
            Items = data
        end property
 
        ' Set the item at the specified index of the array.
        public property let Item(position, value)
            'Make sure position >= lbound(data)
            if position < lbound(data) then
                exit property
            end if
 
            if position > ubound(data) then
                'We need to resize the array
                redim preserve data(position)
                data(position) = value
            else
                'We don't need to resize the array
                data(position) = value
            end if
        end property
 
        ' Remove the item from the specified index of the array.
        public sub Remove(position)
            dim i
 
            'Make sure position is within acceptable ranges.
            if position < lbound(data) or position > ubound(data) then
                'Invalid range.
                exit sub
            end if
 
            for i = position to ubound(data) - 1
                data(i) = data(i + 1)
            next
 
            redim preserve data(ubound(data) - 1)
        end sub
 
        ' Erase the entire contents of the array.
        public sub RemoveAll()
            redim data(0)
        end sub
 
        ' Add an item to the array.
        public sub Add(value)
            redim preserve data(ubound(data) + 1)
            if isObject(value) then
                set data(ubound(data)) = value
            else        
                data(ubound(data)) = value
            end if
        end sub
 
        ' Perform a binary search on the values in the array.
        private function BinarySearch(value, startPosition, endPosition)
            dim midPoint
 
            if startPosition = endPosition then
                'Array only contains one item.
                if value = data(startPosition) then
                    BinarySearch = startPosition
                else
                    'Where it would have been...
                    BinarySearch = -(startPosition)
                end if
            elseif startPosition > endPosition then
                'Can't search backwards.
                BinarySearch = -(startPosition)
            else
                'Array contains multiple items.
                midPoint = clng(startPosition + ((endPosition - startPosition) / 2))
 
                'if we're lucky, the value is at the midpoint.
                if value = aTheList(midPoint) then
                    BinarySearch = midPoint
                else
                    'Determine on which side of the midpoint to look for the value.
                    if value < data(midPoint) then
                        BinarySearch = BinarySearch(value, startPosition, midPoint - 1)
                    else
                        BinarySearch = BinarySearch(value, midPoint + 1, endPosition)
                    end if
                end if
            end if
        end function
 
        ' Check if an item exists in the array.
        public function Exists(value)
            Exists = BinarySearch(value, lbound(data), ubound(data))
        end function
 
        ' Select a random item from the array.
        public function Random()
            Random = data(Int((uBound(data) - lBound(data) + 1) * Rnd + lBound(data)))
        end function
 
        ' Reverse the order of the items in the array.
        public function Reverse()
            for i = 0 to Round(ubound(data) / 2)
                call Swap(lbound(data) + i, ubound(data) - i)
            next
        end function
 
        ' Sort the array alphanumerically.
        public sub Sort()
            call QuickSort(lbound(data), ubound(data))
        end sub
 
        ' Quick sort is the fastest sort algorithm provided by this class.
        private sub QuickSort(loBound, hiBound)
            dim pivot
            dim loSwap
            dim hiSwap
 
            if hiBound - loBound = 1 then
                if data(loBound) > data(hiBound) then
                    call Swap(loBound, hiBound)
                end if
            end if
 
            pivot = data(cint((loBound + hiBound) / 2))
            data(cint((loBound + hiBound) / 2)) = data(loBound)
            data(loBound) = pivot
            loSwap = loBound + 1
            hiSwap = hiBound
 
            do
                do while loSwap < hiSwap and data(loSwap) <= pivot
                    loSwap = loSwap + 1
                loop
 
                do while data(hiSwap) > pivot
                    hiSwap = hiSwap - 1
                loop
 
                if loSwap < hiSwap then
                    call Swap(loSwap, hiSwap)
                end if
            loop while loSwap < hiSwap
 
            data(loBound) = data(hiSwap)
            data(hiSwap) = pivot
 
            if loBound < (hiSwap - 1) then
                call QuickSort(loBound, hiSwap - 1)
            end if
 
            if hiSwap + 1 < hibound then
                call QuickSort(hiSwap + 1, hiBound)
            end if
        end sub
 
        ' This sorting method is not used by this class because it is slow, but is provided here for fun.
        private sub BubbleSort()
            dim i
            dim j
 
            for i = ubound(data) - 1 to 0 step -1
                for j = 0 to i
                    if data(j) > data(j + 1) then
                        call Swap(j + 1, j)
                    end if
                next
            next
        end sub
 
        ' This sorting method is not used by this class because it is slow, but is provided here for fun.
        private sub CombSort()
            dim i
            dim gap
            dim isSwapped
            dim arraySize
 
            const shrink = 1.3
 
            arraySize = ubound(data)
            gap = arraySize - 1
 
            do
                gap = Int(gap / shrink)
                isSwapped = true
 
                for i = 0 to arraySize - gap
                    if data(i) > data(i + gap) then
                        call Swap(i, i + gap)
                        isSwapped = false
                    end if
                next
            loop until not isSwapped and gap = 1
        end sub
 
        ' This sorting method is not used by this class because it is slow, but is provided here for fun.
        private sub ExchangeSort()
            dim front
            dim back
            dim arraySize
 
            arraySize = ubound(data)
 
            for front = 0 to arraySize
                for back = front to arraySize
 
                    if data(front) > data(back) then
                        call Swap(front, back)
                    end if
                next
            next
        end sub
 
        ' This sorting method is not used by this class because it is slow, but is provided here for fun.
        private sub SelectionSort
            dim front
            dim back
            dim location
            dim arraySize
 
            arraySize = ubound(data)
 
            for front = 0 to arraySize - 1
                location = front
 
                for back = front to arraySize
                    if data(location) > data(back) then
                        location = back
                    end if
                next
 
                call Swap(location, front)
            next
        end sub
 
        ' Randomize the order of the items in the array.
        public sub Shuffle
            dim i
 
            randomize timer
 
            for each i in data
                call Swap(i, int(rnd * (ubound(data) + 1)))
            next
        end sub
 
        ' Swap two specified items in the array; used by sorting algorithms.
        private sub Swap(x, y)
            dim temp
 
            temp = data(x)
            data(x) = data(y)
            data(y) = temp
        end sub
 
        ' Return the sum of the values of the array.
        public function Sum()
            dim i
            dim result
 
            result = 0
 
            ' Only numeric items can be added.
            for each i in data
                if isNumeric(i) then
                    result = result + i
                end if
            next
 
            Sum = result
        end function
 
        ' Return the product of the values of the array.
        public function Product()
            dim i
            dim result
 
            result = 0
 
            ' Only numeric items can be multiplied.
            for each i in data
                if isNumeric(i) then
                    result = result * i
                end if
            next
 
            Product = result
        end function
 
        ' Destructor
        private sub Class_Terminate
            data = nothing
        end sub
    end Class
%>