问扩展DOM元素的功能

EN

$('#maindiv')
    .css({left: 100, top: 250})
    .fadeOut(1000)
    .addClass('.foo')
    .toggleClass('.inactive', $(this).is(':checked'))
;

function _(selector) {
    var obj = {
        el: document.getElementById(selector),
        css: function (attributes, values) {
            /* ... */

            return obj;
        },
        fadeOut: function (speed) {
            /* ... */

            return obj;
        }
    };

    return obj;
}