无法接收选定的复选框PHP

I have two separate group boxes like so:

<form id = "query" method = "post" action = "search.php">

<input type = "checkbox" name = "col_list[]" value = "cheese">cheese</input>
<input type = "checkbox" name = "col_list[]" value = "tomatoes">tomatoes</input>

<input type = "checkbox" name = "col_order[]" value = "italian">italian</input>
<input type = "checkbox" name = "col_order[]" value = "wheat">wheat</input>

<input id = "submit" name = "submit" type = "submit" value = "submit" display = "inline></input>

</form>

These group boxes will change depending upon a value selected from a drop-down menu above it (done in javascript). For example, if the value of sandwich is selected, then these two group boxes will be displayed, however, if the value of pizza was selected, there would be a group box with various toppings and another with the types of crust. I can post that code if needed

In my PHP code, I have:

$columns = $_POST["col_list"];
$order = $_POST["col_order"];

I attempt to print both of the arrays, yet I am always met with a screen that takes forever to load, followed by my "error" message that found both the arrays to be empty (I simply used the empty(var) method).

If I select any amount of top boxes, but no boxes on the separate group, then my code is fine and I have all of the selected values of the first group. However, if I compound onto that and select any amount from the second group, the problem ensues.

I have no idea as to why they would be empty. Any thoughts?

Naming two checkbox with the same name parameter is a mistake... probably if one col_list array has some elements, the other is empty... so the $_POST will return a empty array. Try naming your checkboxes with differente names and change your javascript

try this:

if (is_array($_POST['col_list'])) {
     foreach($_POST['col_list'] as $result) {
        ...
     }
}

Edit: Duplicate name fields are permissible in PHP. Thanks to Quentin for pointing this out.

The name field of the input tag is used as the key for POST and GET queries. You need to match them exactly, like:

$columns = $_POST["col_list[]"];
$order = $_POST["col_order[]"];

Unless there is some crazy array syntax that nobody told me about...

Also, I would refrain from using the same value for the name field for multiple fields as it has to choose one of them to send and you may not like which field it sends to you. Instead, try disabling/removing the component when your form's submit method is called, or simply assign all your input fields with unique names.