PHP Arrays and Form Values - php

Question

PHP noob here. I am using PHP to present a supply order form. The list of supplies that can be ordered are dynamic, so I'm pulling them from a MySQL database. Here is the PHP code that is generating the HTML form fields by looping through the results of the query:
while($row = mysqli_fetch_array($itemresult))
{
echo "<input type='hidden' name='Item_ID[]' value='" . $row['Item_ID'] . "'></TD>";
echo "<TR><TD class='itemdesc'>" . $row['Item_Name'] . " </TD>";
echo "<input type='hidden' name='Item_Name[]' value='" . $row['Item_Name'] . "'></TD>";
echo "<TD>" . $row['Item_Qty'] . " </TD>";
echo "<TD class='itemprice'>" . $row['Price'] . " </TD>";
echo "<input type='hidden' name='Item_Price[]' value='" . $row['Price'] . "'></TD>";
echo "<TD><input type='text' size='3' name='Order_Qty[]'></TD>";
echo "<TD><input type='checkbox' name='Off_Day[]'></TD>";
}
I have no experience using arrays, however it makes sense that I need these form values passed to my process.php file in an array format. For now, the purpose of my process.php is to simply print a list of Item_Name and the associated Order_Qty by themselves, pretty much like:
Pencils 10
Pens 7
and on and on.
Being new to arrays and PHP, I have no idea how to accomplish this in my process.php files and would appreciate some guidance. Thanks!
+++++++++++++++++++++++++++++++++++++++++++++++
*#yknivag*
Thank you! That helps me understand me the structure. I've been testing various foreach examples online, am hitting a roadblock and could use some additional help. My array result looks like this.
[Item_Name] => Array (
[0] => One Item
[1] => Second Item
[2] => Third Item
[3] => Fourth Item )
[Item_Price] => Array (
[0] => 0.00
[1] => 64.50
[2] => 110.00
[3] => 38.45 )
How do I reference a particular value in the array, such as 'Second Item'? I can't seem to figure out the syntax for referencing a particular item. For instance, this statement returns no data.
echo "Item: " . $_POST[Item_Name] . "<BR>";
What would also be helpful, is to know how to display corresponding array items such as 'Second Item' and '64.50' together?
The following foreach loop seems like it should do the trick, however it doesn't return any data either.
foreach ($myarray as $key => $value)
{
echo "<p>".$key." ".$value."</p>";
}
Everything I've read says this should give me what I want, and I'm confused as to why it's returning nothing.

Answer 1

In your process.php file begin with:
<?php
print "<pre>" . PHP_EOL;
print_r($_POST);
print "</pre>" . PHP_EOL;
?>
Then you will see the structure of the data which is being sent back and that should help you to work out how to process it.
Once you have the structure, examine the foreach command.

Answer 2

You want an associative array
array("pencil" => 9.99, "pen" => 3.23, "paper" => 21.11)
If you are submitting your form through AJAX, you would use JavaScript to post the values to your PHP page.
var pencil = document.getElementById("pencil").value;
var pen = document.getElementById("pen").value;
var paper = document.getElementById("paper").value;
$.post("process.php", {pencil: pencil, pen: pen, paper: paper});
On your "process" page, you would grab the values that were posted
$pencil = $_POST["pencil"];
$pen = $_POST["pen"];
$paper = $_POST["paper"];
then build your array with the following
$myarray = array("pencil" => $pencil, "pen" => $pen, "paper" => $paper);
Edit
In your WHILE loop, build yourself an array by putting this at the end
$myarray[$name] = $price;
Then outside of the loop, encode your array into a JSON object
$myjson = json_encode($myarray, JSON_HEX_APOS);
Now that you have a JSON object, you'll need to grab it in JavaScript
var myjson = <?php echo $myjson; ?>;
Then you can do whatever you want with the key / value pairs
for(var key in myjson){
var item_name = key;
var item_price = myjson[key];
//where the magic happens
}