Question

I found several solutions for hiding divs when they are empty but not in connection with a mysql retrieved value.

<button class="platform_category" id="platform_', $platform['platform_id'],'_category"><a href="', $platform['platform_url'],'" target="_tab">', $platform['platform_category1'],'</a></button>

Jquery does not hide div when there is no data in mysql-row because it thinks $platform[‘platform_category1’] is a value even though that is only the php-code to retrieve the mysql value in case there is one.

For the hiding jquery code I am using this:(if I replace the == with != it hides)

    $(function() {
    $('.platform_category').each(function() {
        if ($(this).html() == "") {
             $(this).hide();
       }
    }); 
});

Answer 1

Buttons with class platform_category have <a> tag as inner html, so html() method does not make any sense here (it will always return <a>). Try text() instead:

$('.platform_category').each(function() {
    if ($(this).text() == "") {
        $(this).hide();
    }
});

GOOD NOTE (from @Blazemonger): It is good to use text trimming with $.trim() method:

if ($.trim($(this).text()) == "") {
    $(this).hide();
}