Question

i am tryng to get all the td from each row in which colspan attribute is not defined

$('tr').each(function () {
   $(this).find('td').each(function () {
     if (($(this).text().trim() == ""))  && // and this td not has colspan attribute {
       $(this).closest("td").remove();
       };
    });
 });

Answer 1

As per OP comment, he want to remove the td with no colspan and empty value. i guess this can be done that in one line. try this

$('td:empty:not([colspan])').remove();

fiddle : http://jsfiddle.net/F92De/1/