[RESOLVED] PHP Math Question (Simple Addition)

nullfactor

I am designing a custom shopping cart that fits my specific needs (where a lot of the pre-built carts really fell short). The design of the shopping cart has gone relatively smoothly, up to this point. I ran into a problem that seems like should be easy to solve, but I am drawing a total blank:

I do not know how many items will be in the cart (one variable that I do not know the real number for), but each line will have a $subTotal variable where I multiply $qty and $itemPrice. I need to get the sum of all of the $subTotals in the cart, but I cannot figure out how to do so.

If anybody can give me a hand, I would totally appreciate it.
If you require any additional information, please let me know.

NogDog

I suspect we'll need more information. What are we summing: array elements, rows/columns in a database, an object that is a collection of other objects and implementing an object iterator, or what?

nullfactor

First, thank you for the reply.

After walking away from it for awhile, I was able to reach my goal. It turns out that the brunt of the resolution was in the MySQL statement, rather than the PHP code. I was able to get the math by using the SQL statement:

$query = mysql_query("SELECT sum(qty*price) FROM cart WHERE cartID='" .$cartID. "'");

Then, wrapped in a WHILE loop, I get the appropriate sum using a PHP variable.

Don't know if that is the easiest way of doing things, but it works wonderfully, so I'm happy!

Again, thanks for the reply. I will be marking this as RESOLVED!