Very new and struggling my way through a book. The exercise is around a simple shopping cart page.
I have updated the code with some isset() to clear a few undefined notices, but there are a couple I am totally stuck with.
The code is:
Code: Select all
<?php
//start session
session_start();
//initialise the session shopping cart
if (!isset($_SESSION['cart']))
{
$_SESSION['cart'] = array();
}
//find the catalogue
$catalogFile = "catalogue.dat";
//file is available extract data from it
//place into an array called $CATALOG with sku as the key
if (file_exists($catalogFile))
{
$data = file($catalogFile);
foreach ($data as $line)
{
$linearray = explode (':', $line);
$sku = trim ($linearray[0]);
$CATALOG[$sku] ['desc'] = trim ($linearray[1]);
$CATALOG [$sku] ['price'] = trim ($linearray[2]);
}
}
else
{
die ("could not find file");
}
//check to see if the form has been submitted and which submit button was clicked
//if this is an add operation add to existing quantities in the cart
if (isset($_POST['add']))
{
foreach ($_POST['a_qty'] as $k => $v)
{
//if the value is zero do not bother changing the cart
if ($v > 0)
{
$_SESSION['cart'][$k] = $_SESSION['cart'][$k] + $v;
}
}
}
//if this is an update to the cart operation replace quantities
//in the cart with values entered
else if (isset($_POST['update']))
{
foreach ($_POST['u_qty'] as $k => $v)
{
//if value is empty negative or zero dont update the cart
if ($v != "" && $v >= 0)
{
$_SESSION['cart'][$k] = $v;
}
}
}
//if this is a clear operation reset the cart and destroy session
else if (isset($_POST['clear']))
{
$_SESSION = array();
session_destroy();
}
?>
<html>
<head></head>
<body>
<h1>Catalogue</h1>
<form action="" method="post">
<table border="0" cellspacing="10">
<?php
//print items for selection in a form
foreach ($CATALOG as $k => $v)
{
echo "<tr><td colspan=2>";
echo "<b>" . $v['desc'] . "</b>";
echo "</td></tr>\n";
echo "<tr><td>";
echo "Price per unit: " . $CATALOG[$k]['price'];
echo "</td><td>Quantity: ";
echo "<input size=4 type=text name=\"a_qty[" . $k . "]\">";
echo "</td></tr>\n";
}
?>
<tr>
<td colspan="2">
<input type="submit" name="add" value="add to cart">
</td>
</tr>
</table>
<hr />
<hr />
<h2>Cart</h2>
<table width="500" border="1" cellspacing="10">
<?php
//initialise a variable to hold total cost
$total = 0;
//checl the cart and if it contains values look up the sku in the $CATALOG array
//get the cost and calculate sutotal and total
if (is_array($_SESSION['cart']))
{
foreach ($_SESSION['cart'] as $k => $v)
{
//only display items thyat have been selected, ie, qunatitiees greater then zero
if ($v > 0)
{
$subtotal = $v * $CATALOG[$k]['price'];
$total += $subtotal;
echo "<tr><td>";
echo "<b>$v unit(s) of " . $CATALOG[$k]['desc'] . "</b>";
echo "</td><td>";
echo "New qty: <input size=4 type=text name=\"u_qty[" . $k . "]\">";
echo "</td><td>";
echo "Price per unit; " . $CATALOG[$k]['price'];
echo "</td><td>";
echo "Sub total: " . sprintf("%0.2f", $subtotal);
echo "</td></tr>\n";
}
}
}
?>
<tr>
<td><b>TOTAL</b></td>
<td><b><?=sprintf("%0.2F", $total)?></b></td>
</tr>
<tr>
<td><input type="submit" name="update" value="update cart""></td>
<td><input type="submit" name=" clear" value="clear cart"></td>
</tr>
</table>
</form>
</body>
</html>
The messages I cannot figure out how to solve are:
Notice: Undefined offset: 101 in C:\xampp\htdocs\stuff\cart.php on line 43
Notice: Undefined index: cart in C:\xampp\htdocs\stuff\cart.php on line 110
If someone could explain what those noties mean and how they are fixed that would help me learn thank you.
Also, the book I am using is a few years old. Is the php above up to date and well written or should I be using a newer teaching source?
