Save multiple checkboxes in users profile

Hello all,

I’m helping a customer build a “simple” plugin, which lists post categories on their profile-page, and then they can tick a checkbox if they are interested in recieving an email regarding the respective category.

My problem right now is, I can’t seem to save my data!

Here’s the code for my checkboxes:

foreach( $rdc_taxonomies as $tax ) { ?>

        <li><input type="checkbox" id="rdc_usermeta_checkbox" name="checkbox_data" value="<?php echo $tax->slug; ?>" /><?php echo $tax->name ?></li>

    <?php } ?>

But, as I said, there might be 4-5 checkboxes, so I need a way to save data for each one of them. Any ideas on how I accomplish that correctly?

My brain has simply turned off for now – but I really want to get it done 🙂
I hope someone can help me out – or guide me.

Best regards
Aris Kuckovic