PHP: Array > Sum all the numeric elements? - php

Question

I found a reference in the PHP manual, but my interpretation is pretty much wrong:
$total = (sum ( array $_SESSION['list'][$item]['price'] ));
I want to sum the price of all the items in the array SESSION.
Please check the screenshot: http://img684.imageshack.us/img684/6070/20110430010324.jpg
This is the code I'm using:
<?php
session_start();
//Getting the list
$_SESSION['list'] = isset($_SESSION['list']) ? $_SESSION['list'] : array();
//stock
$products = array(
'Pineaple' => 500, 'Banana' => 50, 'Mango' => 150,
'Milk' => 500, 'Coffe' => 1200, 'Butter' => 300,
'Bread' => 450, 'Juice' => 780, 'Peanuts' => 800,
'Yogurt' => 450, 'Beer' => 550, 'Wine' => 2500,
);
//Saving the stuff
$new_item = array(
'item' => $_POST['product'],
'quantity' => $_POST['quantity'],
'code' => $_POST['code'],
'price' => $products[$_POST['product']] * $_POST['quantity'],
);
$new_product = true;
foreach($_SESSION['list'] as $key => $item) {
if ($item['item'] == $new_item['item']) {
$_SESSION['list'][$key]['quantity'] += $new_item['quantity'];
$_SESSION['list'][$key]['price'] = $products[$new_item['item']] * $new_item['quantity'];
$new_product = false;
}
}
if ($new_product) {
$_SESSION['list'][] = $new_item;
}
//listing
echo "<b>SHOPPING LIST</b></br>";
foreach($_SESSION['list'] as $key => $item) {
echo 'Product .'. $key. ' '. $item['item'], ' ', $item['quantity'], ' units: ', $item['price']. '<br />';
}
echo "</br> <a href='index.html'>Return to index</a> </br>";
//Printing session
var_dump($_SESSION);
//session_destroy();
?>

Answer 1

$total = 0;
foreach($_SESSION['list'] as $item) {
$total += $item['price'];
}
Or if you prefer a functional style (PHP 5.3):
$total = array_reduce($_SESSION['list'], function($a, $b) {
return $a['price'] + $b['price'];
});