Question

I have this array in ASP

CONST CARTPID = 0
CONST CARTPRICE = 1
CONST CARTPQUANTITY = 2
dim localCart(3,20)

I add items to this array dynamically like this

localCart(CARTPID,i) = productId
localCart(CARTPRICE,i) = productPrice
localCart(CARTPQUANTITY,i) = 1

The problem is, after 4 items, I can still add the items but UBound always return 3. Which causing my conditions failing.

I want to increase size of this array at run time so that UBOUND can return latest value.

Please let me know how can i do that. Here is my complete code

'Define constants
 CONST CARTPID = 0
 CONST CARTPRICE = 1
 CONST CARTPQUANTITY = 2

 'Get the shopping cart.
 if not isArray(session("cart")) then
dim localCart(3,20)
 else
localCart = session("cart")
 end if

 'Get product information
 productID = trim(request.QueryString("productid"))
 productPrice = trim(request.QueryString("price"))

 'Add item to the cart

 if productID <> "" then
foundIt = false
for i = 0 to ubound(localCart)
    if localCart(CARTPID,i) = productId then
        localCart(CARTPQUANTITY,i) = localCart(CARTPQUANTITY,i)+1
        foundIt = true
        exit for
    end if
next
if not foundIt then
    for i = 0 to 20

        if localCart(CARTPID,i) = "" then
                            ***ReDim Preserve localCart(UBound(localCart, 1) + 1,20)***
            localCart(CARTPID,i) = productId
            localCart(CARTPRICE,i) = productPrice
            localCart(CARTPQUANTITY,i) = 1
            exit for
        end if
    next
end if
 end if

Answer 1

I think redimentioning the array with the current UBound+1 after each addition of new item will make UBound gives you the latest value finally.

// New item addition code will go here
ReDim localCart(UBound(localCart, 1) + 1,20)

So it will update your array with the new size every time you will add the new item.