How do I populate subtotal var using cfloop collection?

[Guest]

I have redesigned a simple shopping cart that uses cfloop collection. What I am trying to do is figure out how to add all prices into a subtotal variable, but I can't get it to work. Below is the basics of what I am using:

<cfloop collection="#session.cart#" item="i">

///////////// definitions

session.cart[1] = prod_id

session.cart[2] = prod_name

session.cart[3] = price

session.cart[4] = Date

session.cart[5] = quantity

//////////// Script to add or delete item

<cfscript>

if (not(isdefined("session.cart"))) { // Check to make sure that the Shopping cart structure exists.

session.cart = structnew();                                                                         

                }

// The item structure we are going to use to store the items in the cart is going to have five parts...

// 1.  The product id

                // 2.  The item name

                // 3.  The price per unit

                // 4.  The Sale Date

                // 5.  The quantity

tempvalue = listtoarray('#attributes.id#,#attributes.name#,#attributes.price#,#attributes.date#,#attributes.quantity#');

// if the item is not yet in the cart, simply add it to the cart

if (not(structKeyExists(session.cart, attributes.name))) {

                StructInsert(session.cart,attributes.name,tempvalue);

                }

// if the item is already in the cart, update the item quantity

                else {

                                tempvalue[5]=session.cart[attributes.name][5]+attributes.quantity;

                                StructUpdate(session.cart,attributes.name,tempvalue);

                                }                                             

</cfscript>

//////////// Once quantity has been changed I use the following to change the price

<cfset newPrice = (session.cart[5] * session.cart[3])>

----------------------------------------------------------------------

The cart shows:

|  product name  (session.cart[2])   |  quantity ( session.cart[5])   |  newPrice  (session.cart[5] * session.cart[3]) |

How do I add up the newPrice column to give me a subtotal?

[insuractive · Accepted solution]

It looks like your newprice var is being used to report on the cost of the line item in your cart (e.g. cost * units).  You have a few ways to tracking the subtotal for all items:

1) If you are not displaying the value of "newprice" in your interface, you could use a += operator to add the value of each entry in your array when you assign it:

<cfset newPrice += (session.cart[5] * session.cart[3])>

2) You could create a variable to hold the totalPrice that you add your newPrice value to for each iteration of your array:

<cfset newPrice = (session.cart[5] * session.cart[3])>

<cfset totalPrice += totalPrice>

3) You could perform your subtotal calculation in your code where you need to display the total by looping through your array and generating the totals:

<cfset fSubTotal  = 0>

<cfloop array="#session.cart#" item="arrCartItem">

     <cfset fSubTotal += arrCartItem[3] * arrCartItem[5]>

</cfloop>

[Guest]

Thanks for the help. I had to alter the code, but you gave me the right direction to follow:

<cfset fSubtotal  = 0>
     <cfloop collection="#session.cart#" item="i">
     <cfset fSubtotal += (session.cart[3] * session.cart[5])>
</cfloop>

It works perfectly.