jQuery: how to return all elements that has been .data("tag","tagged")?

$('*').data('tag', "tagged"); 

$('li[tag=tagged]').length retur开发者_开发百科ns zero...

$('*').data('tag', "tagged");

$('li').each(
    function()
    {
        if( $(this).data('tag') === "tagged" )
        {
            //do something taggy ...like increment a count
        }
    }
);

Or, for something reuseable:

function getTaggedInJquery( jQueryObj )
{
    var total = 0;
    jQueryObj.each(
        function()
        {
            if( $(this).data('tag') === "tagged" )
                total++;
        }
    );
    return total;
}

alert( getTaggedInJquery( $('li') ) );

AFAIK the data(..) method doesn't really set/append/create anything on the element you use it on.

It uses an internal dictionary object to hold the values and matches them via a uniquely generated id.

The solution proposed by Kevin Peno works but can get very costly very quick if you don't choose your selectors wisely.

Check http://jqueryjs.googlecode.com/files/jquery-1.3.2.js around line 1271++-

The selector you're using matches attributes on the HTML element, not jQuery data items.

AFAIK, jQuery has no built-in selector that matches data items.

You can either write your own selector or set your own attributes on the elements themselves.

var taggedElements = $.grep($('li').get(), function(n, i){
    return ($(n).data('tag') == 'tagged');
});