var testLimit = {
    init: function (p) {
        var regional = undefined;
        p = $.extend(true, {
            edit: true,
            add: true,
            del: true,
            search: true
        }, regional, p || {});
        console.log(p.edit + "," + p.add + "," + p.del);
    }
}
 

   $(document).ready(function () {
        testLimit.init();
        testLimit.init({add: false, edit: false});
});

結果：

true,true,true
false,false,true