Can't delete without getting "Undefined Offset" error

Question

I'm doing a very simple project for my assignment and it's about shopping cart. I've created a cart page by using SESSION with array and index to keep track user's order. The problem is whenever I'm deleting a meal from my cart list, there'll be an error which is "Notice: Undefined offset: 1", "Notice: Undefined offset: 2", etc. I'm attaching my codes here:

This is my cart page. The error said it has something to do on the line that I have commented:

<form method="POST" action="save_cart.php">
<table class="table">
<tbody>

<thead>
      <th></th>
      <th>Name</th>
      <th>Price</th>
      <th>Quantity</th>
      <th>Subtotal</th>
</thead>


  <?php
        //initialize total
        $total = 0;
        if(!empty($_SESSION['cart'])){

        //create array of initail qty which is 1
        $index = 0;
        if(!isset($_SESSION['qty_array'])){
          $_SESSION['qty_array'] = array_fill(0, count($_SESSION['cart']), 1);
        }
        $sql = "SELECT * FROM meal WHERE meal_id IN (".implode(',',$_SESSION['cart']).")";
        $query = $conn->query($sql);
          while($row = $query->fetch_assoc()){
            ?>

          <tr>

              <td class="removebtn" style="text-align: center;">
                <a href="delete_item.php?id=<?php echo $row['meal_id']; ?>&index=<?php echo $index; ?>" >Remove</a>
              </td>
              <td><?php echo $row['meal_name']; ?></td>
              <td>RM <?php echo number_format($row['meal_price'], 2); ?></td>
              <input type="hidden" name="indexes[]" value="<?php echo $index; ?>">
              <td class="qtyinput" ><input type="number" min="1" max="5" class="form-control" value="<?php echo $_SESSION['qty_array'][$index]; ?>" name="qty_<?php echo $index; ?>"></td>

              //THE ERROR IS HERE

              <td>RM <?php echo number_format($_SESSION['qty_array'][$index]*$row['meal_price'], 2); ?></td>
              <?php $total += $_SESSION['qty_array'][$index]*$row['meal_price']; ?>
            </tr>
            <?php
            $index ++;
          }
        }
        else{
          ?>
          <tr>
            <td colspan="5" class="text-center"  style="text-align: center;">No Meal in Cart</td>
          </tr>
          <?php
        }

      ?>
      <tr>
        <td colspan="4" align="left"><b>Total</b></td>
        <td><b>RM <?php echo number_format($total, 2); ?></b></td>
      </tr>
</tr>

Here's my delete page:

session_start();

//remove the id from our cart array
$key = array_search($_GET['meal_id'], $_SESSION['cart']);   
unset($_SESSION['cart'][$key]);

unset($_SESSION['qty_array'][$_GET['index']]);
//rearrange array after unset
$_SESSION['qty_array'] = array_values($_SESSION['qty_array']);

$_SESSION['message'] = "<script>alert('Meal is deleted from your cart');</script>";
header('location: cart.php');

I really need your help. Thanks in advance!

you re trying to run out of bounds of the array meaning the array size is smaller than the index that you are trying to fetch an object from. — Dorvalla, Dec 05 '18 at 11:51
@Dorvalla How do I fix it sir? I'm a beginner so I really have no idea. I hope you can help me — znf96, Dec 05 '18 at 11:59
Duplicate of https://stackoverflow.com/questions/4261133/notice-undefined-variable-notice-undefined-index-and-notice-undefined — maio290, Dec 05 '18 at 12:01

Ashfaque Ali Solangi · Answer 1 · 2018-12-05T13:09:15.527

1

Its an index error because index doesn't exists in the array replace your html php code inside while loop with this one.

<tr>

<td class="removebtn" style="text-align: center;">
<a href="delete_item.php?id=<?php echo $row['meal_id']; ?>&index=<?php echo $index; ?>" >Remove</a>
</td>
<td><?php echo $row['meal_name']; ?></td>
<td>RM <?php echo number_format($row['meal_price'], 2); ?></td>
<input type="hidden" name="indexes[]" value="<?php echo $index; ?>">
<td class="qtyinput" ><input type="number" min="1" max="5" class="form-control" value="<?php echo (isset($_SESSION['qty_array'][$index]) ? $_SESSION['qty_array'][$index] : 0); ?>" name="qty_<?php echo $index; ?>"></td>

//THE ERROR IS HERE

<td>RM <?php 
$qty = (isset($_SESSION['qty_array'][$index]) ? $_SESSION['qty_array'][$index] : 0);
echo number_format($qty *$row['meal_price'], 2); ?></td>
<?php $total += $qty*$row['meal_price']; ?>
</tr>

edited Dec 05 '18 at 13:09

answered Dec 05 '18 at 12:08

Ashfaque Ali Solangi

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Thank you sir, but the Undefined Offset is still there when I remove the items. It's on the line . And the item doesn't removed from the list. I've attached the pic above. How do I fix it, sir? – znf96 Dec 05 '18 at 12:21
i think the issue is with query maybe that is not checking the actual item is in cart or not ? can you print this query $sql = "SELECT * FROM meal WHERE meal_id IN (".implode(',',$_SESSION['cart']).")"; echo $sql;exit(); and check what results come out. – Ashfaque Ali Solangi Dec 05 '18 at 12:51
can you replace this line $total += $_SESSION['qty_array'][$index]*$row['meal_price']; with $total += $qty*$row['meal_price']; – Ashfaque Ali Solangi Dec 05 '18 at 13:01
Hi sir, can I have your email? I want to ask some questions about the problems I'm having with my project. I hope you don't mind. – znf96 Dec 07 '18 at 18:29
@znf96 you can contact at info@ashfaqsolangi.com – Ashfaque Ali Solangi Dec 07 '18 at 20:19

Can't delete without getting "Undefined Offset" error

1 Answers1