PHP Arrays and Javascript Validation

lampfire

Hey folks. I'm wondering if anyone has ever solved this problem.

Say I have a form, with a series of checkboxes that I have named in such a way that the checked items will be placed into an array in PHP.

<form method="post" action="foo.php">
    <input type="checkbox" name="bar[]" value="1"> Item 1<br>
   <input type="checkbox" name="bar[]" value="2"> Item 2<br>
   <input type="checkbox" name="bar[]" value="3"> Item 3<br>
   <input type="checkbox" name="bar[]" value="4">Item 4<br>

<input type="submit">

</form>

How do I write a javascript routine to check that at least one checkbox has been checked? It would seem that by adding the brackets at the end of the name for the form element, the name is not legal under Javascript, and therefore cannot be addressed under the DOM. I've done some research on this and can't find any solutions to this problem. Any workarounds?

Thanks in advance.

bad_goose

If you're using php3 (which looks like the case):

Forget about javascript and do the error checking in php instead- It's more reliable and foolproof that way anyway. Try something like this:

if (!isset($bar)) {
?>

<html>
error page here...
</html>

<?php
exit;
}

That should work, assuming the isset() construct is valid in php3.

If you're using php 4, you could still go with the javascript method, and just change the checkbox names to bar1, bar2, etc. so that javascript can use them. Then in PHP you could recreate the array from those names with the following code, making use of the $_POST array:

foreach ($_POST as $key => $val) {
if (substr($key, 0, 3) == "bar") { $bar[] = $val; }
}

Hope that helps.

franka75

Hi to everyone and sorry for my bad english🙂
I've the same problem, the difference is that I have to use a multiple select structure so I can't have different name for each option!
How can I use my select (with "name[]") with a Javascript function that checks the choice done by the user?

Thanks for the help!

Franka75