PHP Array Variable Being Passed Incorrectly - php

Question

I have a query which is doing something strange. This checkbox is in a while loop and it correctly lists out everything it needs to:
<input type='checkbox' name='rep[]' value='$invoiceID'>Reference Number: $invoiceID
<input type='hidden' name='billablehours[]' value='$billableTotal'>
When the form is submitted the values are inserted into the database using:
foreach ($_POST['rep'] as $index => $id) {
$sql2="INSERT into b_sale_basket (QUANTITY,LID,NAME)
VALUES
('".$_POST['billablehours'][$index]."','s1','".$_POST['rep'][$index]."')";
if (!mysqli_query($con,$sql2))
{
die('Error: ' . mysqli_error($con));
}
}
It inserts everything as it should do except billablehours. I have outputted the value of $billableTotal on each checkbox on the form page and the value is correct. For example it might equal 25 but when the button is pressed it inputs 37.5 which is another value of a checkbox.
Strange. Can anybody identify an issue?

Answer 1

Problem is that if checkbox is not checked it's not passed to server, so if u have 3 checkboxes and select first and third, on server you got them with 0, 1 index.
in your case just use specific identifiers:
<input type='checkbox' name='rep[$id]' value='$invoiceID'>Reference Number: $invoiceID
<input type='hidden' name='billablehours[$id]' value='$billableTotal'>
Assuming you know this $id is connected corresponding $invoiceID and $billableTotal,
it may be entry id from database.
And when using: $_POST['billablehours'][$index] if checkbox is not checked it gots empty...
Note: my exmplanation is just to understand the point, not 100% working example maybe, because I've got no full code what you do.
Just remember: It's the key when working with checkboxes to correctly reference the data passed from server to client and vs.

Answer 2

Only checked checkboxes are submitted. So if you only check one, then rep array will only have one element 0 but thebillablehours array will have as many as are defined on the page.
$i = 0;
//loop
echo "<input type='checkbox' name='rep[$i]' value='$invoiceID'>Reference Number: $invoiceID";
echo "<input type='hidden' name='billablehours[$i]' value='$billableTotal'>";
$i++;
//end loop
So the rep and billablehours indexes will match regardless of how many checkboxes were checked.

Answer 3

You are wide open to SQL injection attacks with your script. You either need to use prepared statements (preferable) or run your $_POST values through mysqli_real_escape_string;
Leaving my incorrect answer below, but not deleting this answer because I think the SQL injection vulnerability needs to be addressed.
That being said, your issue is that you aren't echoing the value:
value='<?php echo $billableTotal; ?>'>

Answer 4

Make these changes:
name="billablehours[$invoiceID]"
$_POST['billablehours'][$_POST['rep'][$index]]