PHP undefined index

Question

Heya I get this error message. I've been looking everywhere but I dont know how to fix it? Im a beginner so I'm really confued. Thanks in advance

Notice: Undefined index: cart in /nas/students/j/j39-green/unix/public_html/ISD5/inc/functions.inc.php on line 3

You have no items in your shopping cart

<?php
function writeShoppingCart() {
$cart = $_SESSION['cart'];
if (!$cart) {
 return '<p>You have no items in your shopping cart</p>';
} else {
 // Parse the cart session variable
 $items = explode(',',$cart);
 $s = (count($items) > 1) ? 's':'';
 return '<p>You have <a href="cart.php">'.count($items).' item'.$s.' in your shopping cart</a></p>';
}
}

• Toby Allen: The error is in functions.Inc.php not your code

Answer 1

If $_SESSION['cart'] isn't set, it throws that warning.

Try:

$cart = isset($_SESSION['cart'])?$_SESSION['cart']:false;

Answer 2

Use "EMPTY":

<?php
function writeShoppingCart() {
 $cart = !empty($_SESSION['cart']);
 if (!$cart) {
 return '<p>You have no items in your shopping cart</p>';
 } else {
 // Parse the cart session variable
 $items = explode(',',$cart);
 $s = (count($items) > 1) ? 's':'';
 return '<p>You have <a href="cart.php">'.count($items).' item'.$s.' in your shopping cart</a></p>';
 }
}

Answer 3

This means that the key 'cart' does not exist in the $_SESSION superglobal array.

If it's alright for this value to not exist, you should be doing this:

$cart = false;
if (isset($_SESSION['cart'])) {
 $cart = $_SESSION['cart'];
}

You could use something called the ternary operator, in PHP, but since you're a beginner, I don't want to bombard you.

In development mode, it's alright to display errors but you should read more about disabling errors (error_reporting) and logging them (error_log()) so that they can be inspected without alarming visitors.

Answer 4

That means that your session does not contain $_SESSION['cart']

Try this instead:

$cart = isset($_SESSION['cart']) ? $_SESSION['cart'] : false;

Answer 5

Try this:

$cart = isset($_SESSION['cart']) ? $_SESSION['cart'] : NULL;

Answer 6

try initializing your $_SESSION with something like:

$_SESSION['cart'] = 0; // zero items in cart