javascript - jQuery string-variable as id-selector return empty object -

there i'm not seeing here.. have string-variable elements id:

var sf_new_id = "#sf_widget_choice-32:14.86:1:1" 

i string element this('sf_selectedmethod' element):

var anotherid = sf_selectedmethod.attr('id'); 

then removed last char , add info id, namely last number , '#':

var sf_new_id = anotherid.substr(0, anotherid.length-1); // without last char. sf_new_id = '#'+sf_new_id+'1'; 

and becomes string described above.

and i'm trying access element jquery this:

$(sf_new_id).addclass("..."); 

the element id exists, nothing happens. tried hiding element well:

$(sf_new_id).hide(); 

but still nothing happens.

i put whole element console.debug, , shows empty object:

console.debug($(sf_new_id)); 

outputs: object[] in console

what missing here?

edit: tried escape-thingy, , seems work, problem how can escape colons , such when info in variable?

you have escape special characters in string, form valid selector.

var sf_new_id = "#sf_widget_choice-32:14.86:1:1";  sf_new_id = sf_new_id.replace(/:/g, "\\:")                      .replace(/\./g, "\\.")  $(sf_new_id).hide();