Array for Checkboxes in HTML Forms

1 . Both work, solution with lang[] is much more flexible. For example if you have really long form with a list of checkboxes in a few categories, eg. languages user speaks, countries he visited, cars he drove, and let's say each list consists of 10 elements, then hard coding every one of them is a pain in the ..., on PHP side you'd have to check every element manually, and with an array you can do this:

if (isset($_POST['lang'] && is_array($_POST['lang']){   // let's iterate thru the array   foreach ($_POST['lang'] as $lang)   {      // do some super-magic here      // in your example array elements would be $_POST['lang'] = array('en','fr','es')   }}

2 . Like said above to check if any of the languages was selected check:

if (in_array('en', $_POST['lang']))

3 . If you are going to use jQuery simply use this snippet:

// selector ATTRIBUTE*=VALUE find all tags wchich ATTRIBUTE string contains VALUE$('input[name*=lang]').attr('checked', 'checked'); // check$('input[name*=lang]').removeAttr('checked'); // uncheck

Answers:

1. Either works...depends on whether you want explicit names or an array
2. You can also use array_key_exists()
3. Can you post the javascript code you are using into your question? I'll take a further look...

UPDATE:

Here is a jQuery solution for implementing your onclick handlers:

function checkAll(field){    $(':checkbox[name^="cuisine_"]').each(function(index){        this.checked=true;    });}function uncheckAll(field){    $(':checkbox[name^="cuisine_"]').each(function(index){        this.checked=false;    });}

Note that you really don't need to pass in field, unless you want to generalize this and pass in the string for the startswith pattern (e.g. cuisine_).