CODEWITHSUNDEEP
javascriptphphtmlcheckbox
ThreadPeak
ThreadPeak

Reputation: 149

php get value of unchecked checkboxes

I require the values of unchecked checkboxes to be '0' so I can determine which values have been checked and for all values (checked + unchecked) to be posted ($_POST['chk]). I am using a for loop to create the checkboxes and I am generating a hidden field with a value of '0' (as has been suggested elsewhere on stackoverflow).

There are 4 checkboxes ((count($result)-1) = 4) and when checkbox 1 & 3 are checked while checkbox 2 & 4 are unchecked, the $_POST['chk'] array ends up like this:

Array
(
    [chk] => Array
        (
            [0] => 0
            [1] => 180.00
            [2] => 0
            [3] => 0
            [4] => 100.00
            [5] => 0
        )

I want it to look like this:

Array
(
    [chk] => Array
        (
            [0] => 180.00
            [1] => 0
            [2] => 100.00
            [3] => 0
        )

What am I doing wrong? Is this even possible using a for loop and the hidden checkbox fields?

Javascript:

<script type="text/javascript">
function calculate() {
var el, i = 0;
var subtotal = 0;
while(el = document.getElementsByName("chk[]")[i++]) {
    if(el.checked) { subtotal = subtotal + Number(el.value);}
        }
        var node = document.getElementById("subtotal");
        node.innerHTML = "$" + subtotal + ".00";
        var node = document.getElementById("total");
        node.innerHTML = "$" + (subtotal*<?=$no_nights?>) + ".00";
        }   
</script>

HTML/PHP:

<form id="booking_step2" name="booking_step2" method="POST" action="index.php?p=bookings?s=3">
                <? for ($x=0; $x<=(count($result)-1); $x++) { ?>
                            <input type="hidden" name="chk[]" value="0">
                            <input type="checkbox" name="chk[]" value="<?=$result[$x]['r_rate'];?>" onclick="calculate()">
                   <? } ?>

Upvotes: 0

Views: 1620

Answers (1)

Jon
Jon

Reputation: 437914

You are incorrectly using chk[] as the name of the controls. This will give you one element inside $_POST for each unchecked box, but two for each checked one. And the extra elements might be present anywhere inside the array, so you won't be able to make sense of it.

Instead of this, explicitly specify the same index for each pair of hidden input and checkbox:

<? for ($x=0; $x<=(count($result)-1); $x++): ?>
    <input type="hidden" name="chk[<?=$x?>]" value="0">
    <input type="checkbox" name="chk[<?=$x?>]" value="<?=$result[$x]['r_rate'];?>">
<? endfor; ?>

After doing this a checked box will have exactly the same name chk[N] as the hidden input that precedes it, so it will simply trump that value instead of adding another one at the end of the array.

Upvotes: 1

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