PHP refresh page re-initialises variable to 0

Question

I am adding items to a cart using URL ?action=add. I have not initialised the variable $count and am getting the following errors:

Notice: Undefined index: count in C:\wamp\www\cart.php on line 31

Notice: Undefined index: count in C:\wamp\www\cart.php on line 32

I know I need to define the $count variable. ($count = 0;) But I dont want the page to refresh and have the SESSION variable reset to 0 every time a user adds a new item to the cart. The $count needs to be used as a counter on the next page. How can I do this?

Here is my case code:

switch($action) { 
    case "add":
        if (isset($_SESSION['cart'][$comic_id])) {
            $count=$_SESSION['count']; //LINE 31
            $_SESSION['count']++; //LINE 32
            $_SESSION['cart'][$comic_id]++;

        } else {
            $_SESSION['cart'][$comic_id] = 1;
            }
    break;

After adding if (!isset($_SESSION['count'])) $_SESSION['count'] = 1;

<?php 
if(!isset($_SESSION)) {
     session_start();
}
$total = 0;
$page = 'cart';

$dbname = "crystal_fusion";
$dbhost = "127.0.0.1";
$dbuser = "root";
$dbpwd = "";

$link = mysql_connect($dbhost, $dbuser, $dbpwd);

mysql_select_db($dbname);

if(isset($_GET['comic_id'])){
    $comic_id = $_GET['comic_id'];
} else {
    $comic_id = NULL;}

$action = $_GET['action'];

if($comic_id && !productExists($comic_id)) {
    die("We apologise, but we can't seem to find the comic you were looking for!!!");
}

if (!isset($_SESSION['count'])) $_SESSION['count'] = 1; //added as suggested - now output is correct when adding multiples of 1 item. However, the count is wrong if more than 1 item is added.

switch($action) {
    case "add":
        if (isset($_SESSION['cart'][$comic_id])) {
            $count=$_SESSION['count'];
            $_SESSION['count']++;
            $_SESSION['cart'][$comic_id]++;

        } else {
            $_SESSION['cart'][$comic_id] = 1;
            }
    break;  
    case "remove":
        if (isset($_SESSION['cart'][$comic_id])) {
            $_SESSION['cart'][$comic_id]--;} 
        if($_SESSION['cart'][$comic_id] == 0) unset($_SESSION['cart'][$comic_id]); 
    break;  
    case "empty":
        unset($_SESSION['cart']); 
        session_destroy();
    break;  
}

require('header.php');
require('sidebar.php');
if (isset($_SESSION['cart'][$comic_id])){

    echo "<table border=\"0\" padding=\"10\" width=\"80%\">";
    echo "<td colspan=\"1\" align=\"left\"><a href=\"title.php\">Continue Shopping</a></div>";
    echo "<td colspan=\"6\" align=\"right\"><a href=\"$_SERVER[PHP_SELF]?action=empty\" onclick=\"return confirm('Crystal Fusion: Are you sure you wish to empty your cart?');\">Empty Cart</a></td>"; //empty cart link --Sam                      
    echo "<tr height=\"20px\">";
    echo "<tr height=\"20px\">";
    echo "<td align=center>Image</td><td align=center>Title</td><td align=center>Description</td><td colspan=3 align=center>Copies (+/-)</td><td align=center>Price</td>";
    echo "<tr height=\"20px\">";


    foreach($_SESSION['cart'] as $comic_id => $qty) {   

        $sql = sprintf("SELECT title, description, cost, image_thumbnail
                FROM comic 
                WHERE comic_id = %d;",$comic_id);

        $result = mysql_query($sql);

        if(mysql_num_rows($result) > 0) {

            list($name, $description, $price, $image_thumbnail) = mysql_fetch_row($result);



            $cost = $price * $qty;  
            $total = $total + $cost; 

            $cost = number_format($cost,2);
            $total = number_format($total,2);
            $description =  substr($description, 0, 250);

            echo "<br><tr>";
            echo "<td width=\"10px\" align=\"center\"><img height=100 align=center src=\"$image_thumbnail\">";
            echo "<td align=\"center\">$name</td>";
            echo "<td width=\"40%\" align=\"center\">$description...<a href=comic_dyn.php?comic_id=$comic_id>More Info</td>";
            echo "<td width=\"30px\" align=\"center\"><a href=\"$_SERVER[PHP_SELF]?action=add&comic_id=$comic_id\">+<br></a><td align=\"center\">$qty <td width=\"20px\" align=\"center\"><a href=\"$_SERVER[PHP_SELF]?action=remove&comic_id=$comic_id\">-</a></td>";
            echo "<td align=\"right\">$$cost</td>";
            echo "</tr>";           
        }

    }

    echo "<br><tr><tr height=100px>";
    echo "<td><td><td colspan=\"4\" align=\"right\">Total:</td>";
    echo "<td width=\"60px\" align=\"right\">$$total</td>";
    echo "<tr><td colspan=\"7\" align=\"right\"><a href=\"checkout_html.php\">Proceed to Checkout</a>";
    echo "<tr height=\"50px\">";
    echo "</table>";
}else{

    echo "Your cart is currently empty.";
    echo "<br><br><td colspan=\"1\" align=\"left\"><a href=\"title.php\">Continue Shopping</a></div>";

}

$_SESSION['totnamqty'][]=$name . " " . $qty . " " . $price;

function productExists($comic_id) { 
        $sql = sprintf("SELECT * FROM comic WHERE comic_id = %d;", $comic_id);
    return mysql_num_rows(mysql_query($sql)) > 0;
    }
?>

Community · Accepted Answer · 2020-06-20 09:12:55Z

1

Check these:

You have to initialize sessions using session_start(); as the very first.
Make sure that the $_SESSION['count'] exists and initialized before assigning or performing som operation on it.

edited Jun 20, 2020 at 9:12

CommunityBot

11 silver badge

answered Nov 9, 2012 at 7:29

Praveen Kumar Purushothaman

167k27 gold badges215 silver badges261 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

ThreadPeak Over a year ago

Yes session_start is initialised. If I set $_SESSION['count'] = 0; Then the count will be set to 0 each time the page refreshes. I do not want this to happen.

Praveen Kumar Purushothaman Over a year ago

Initialization of $count and $_SESSION variables?

ThreadPeak Over a year ago

Is there any way around this ?

Praveen Kumar Purushothaman Over a year ago

One way is to, show your full PHP code, if you don't have any issues. :) So that we can see where you have gone wrong. :)

웃웃웃웃웃 · Accepted Answer · 2014-07-19 05:32:32Z

0

Before using somewhere $_SESSION['count'] you have to initialize it. i think you didn't done it and that's why you are getting the notices.

edited Jul 19, 2014 at 5:32

answered Nov 9, 2012 at 7:34

웃웃웃웃웃

12k15 gold badges63 silver badges95 bronze badges

7 Comments

ThreadPeak Over a year ago

Yes, but if I initialise it to 0, the count will reset to 0 each time the page is refreshed.

cHao Over a year ago

@Sam: So, only set it if it's not already set. if (!isset($_SESSION['count'])) $_SESSION['count'] = 0;

웃웃웃웃웃 Over a year ago

initialize the $_SESSION['count']=1 if the user is in login state

웃웃웃웃웃 Over a year ago

if my answer is useful please click my answer as correct answer and please up vote my answer.. thank you dude..

웃웃웃웃웃 Over a year ago

check why the count is incrementing... or if you don't want to increment the count and keep it constant define it as a constant

|

Deirdra Strangio · Accepted Answer · 2012-11-09 07:42:31Z

0

Please refer to the following links for more session information:

W3Schools - PHP Sessions

(I would post the PHP.net manual page but I'm new and can only post 2 links)

Also you may also want to transition to using the $_POST variable instead of passing key value pairs through the URL:

PHP.net - $_POST

answered Nov 9, 2012 at 7:42

Deirdra Strangio

1721 silver badge10 bronze badges

Collectives™ on Stack Overflow

PHP refresh page re-initialises variable to 0

3 Answers 3

Check these:

4 Comments

7 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Check these:

4 Comments

7 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related