使用带有序列化数组的in_array？

I have a serialized value in my mysql db that looks like this:

a:5:{s:4:"name";s:13:"Keith Donegan";s:3:"age";s:2:"21";s:7:"college";s:9:"Spin City";s:8:"category";s:1:"7";s:8:"checkbox";a:2:{i:0;s:1:"3";i:1;s:1:"9";}}

I can output the checkbox array fine, but I need to run it againest another set of ids using in_array but my code doesn't work, surprise! :)

echo $eirepanel_general_options['checkbox']; // used in a foreach loop

See the values 3 & 9, I need to test these.

EDIT: MAIN Code

<?php

$eirepanel_general_options_saved = $_REQUEST['eirepanel_general_options_saved'];
if(isset($eirepanel_general_options_saved))
{
    $eirepanel_general_options_name = $_REQUEST['eirepanel_general_options_name'];
    $eirepanel_general_options_age = $_REQUEST['eirepanel_general_options_age'];
    $eirepanel_general_options_college = $_REQUEST['eirepanel_general_options_college'];
    $eirepanel_general_options_category = $_REQUEST['eirepanel_general_options_category'];
    $eirepanel_general_options_checkbox = $_REQUEST['eirepanel_general_options_checkbox'];

    $eirepanel_general_options = array
    (
    'name' => $eirepanel_general_options_name,
    'age' => $eirepanel_general_options_age,
    'college' => $eirepanel_general_options_college,
    'category' => $eirepanel_general_options_category,
    'checkbox' => $eirepanel_general_options_checkbox
    );

    update_option('eirepanel_general_options', $eirepanel_general_options);
}
else
{
$eirepanel_general_options = get_option('eirepanel_general_options');
}


$categories = get_categories(); 
foreach($categories as $category)
{ 
    $eirepanel_general_options_string = $eirepanel_general_options['checkbox'];
    $eirepanel_general_options_array = explode(',', $eirepanel_general_options_string);
    echo$cat_ids = explode(',',$category->cat_ID);

    $ids = array(8, 4);

    var_dump($eirepanel_general_options_string);

    ?>


    <?php // <input name="eirepanel_general_options_checkbox[]" type="checkbox" value="<?php echo $category->cat_ID; ?>
        <?php // if($eirepanel_general_options_string == $category->cat_ID ){ echo "checked='checked'"; } <br /> ?>

        <span><?php echo $category->cat_name; ?></span>
        <input name="eirepanel_general_options_checkbox[]" value="<?php echo $category->cat_ID; ?>" type="checkbox" <?php in_array($eirepanel_general_options_string, $ids) ? 'checked="checked"' : '' ?> /> <br />

<?php }

// var_dump($eirepanel_general_options_string);


?>          

unserialize is your friend here!!

run the string containing the array through that function, catch the result and work with that.

$serial = **serial array goes here**;
$array = unserialize($serial);

Then

echo $array['checkbox'];

would function as you would expect.

Use serialize to reverse the effects, if needed.

$serial = serialize($array);

A serialised array is no longer an array but a string export of the array values. To use array functions, you need to return it to an array using unserialize(), then it is an array which you can treat like an array else, it is just a string.