Fatal error: Uncaught Error: Cannot use object of type stdClass as array in C:\xampp\htdocs\MyShoppingList\list.php:487

Question

When I run the code I get the error:

Fatal error: Uncaught Error: Cannot use object of type stdClass as array in C:\xampp\htdocs\MyShoppingList\list.php:487 Stack trace: #0 {main} thrown in C:\xampp\htdocs\MyShoppingList\list.php on line 487;

I'm not sure why?

function updateList() {
    //? Retrieve items from form POST, decode & unserialize using json.  Empty array if not available.
    $items = $_POST['items']
        ? json_decode(base64_decode($_POST ['items'], true)) 
        : [];
    
    //? Check if food and category was supplied.
    if(filter_input(INPUT_POST, 'food') !== "" && filter_input(INPUT_POST, 'category') !== "") {
        //? Add food/category as item to Shopping List
        $items[] = [
            "food" => filter_input(INPUT_POST, 'food'),
            "category" => filter_input(INPUT_POST, 'category'),
        ];
    }

    return $items;
}

<input type="hidden" name="items" value="<?php echo base64_encode(json_encode($items)) ?>">   

<div id="table">
            <table width="100%">
                <?php if ($items) { ?>
                    
                    <?php foreach($items as $item){?>

                            <tr>
                                <td id="dairy">
                                    <?php echo $item['category'];?>
                                </td>
                            </tr>
                        
                        <form>
                            <tr>
                                <td id="data">
                                    <?php echo'';?>
                                    <label class="container">
                                        <input 
                                            id="<?php echo "check${k}"; ?>"
                                            type="checkbox"
                                            name="<?php echo "check${k}"; ?>" 
                                            value="<?php echo $item['food']; ?>">
                                        <span class="checkmark"></span>
                                    </label>
                                </td>
                            </tr>
                        </form>
                    <?php } ?>
                <?php } else { ?>
                    <tr>
                        <td align="center" style="padding: 20px">No items in list.</td>
                    </tr>
                <?php } ?>
            </table>

Answer 1

It's a json_decode problem: It should have true as second parameter in order to get a result as array. In your code this function is used once, but without a second parameter.

This means: Instead of

json_decode(base64_decode($_POST ['items'], true)) 

It should be:

json_decode(base64_decode($_POST ['items']), true)

Or if the second parameter for base64_decode is needed:

json_decode(base64_decode($_POST ['items'], true), true)