javascript - How to multiply the contents of table cells via js? -

i want multiply cells content (only numbers) , using javascript. result displayed in cell x

<script type="text/javascript"> function zmiana(){     var x = document.getelementbyid("rowstawka");     x.getelementsbytagname('td')[1].innerhtml=document.getelementbyid('stawka2').value;      var y = document.getelementbyid("rowgodziny");     y.getelementsbytagname('td')[1].innerhtml=document.getelementbyid('godziny').value;    } </script> 

i'm using above script add content cells in table.

and here table:

<table id="tabela"> <tr id="rowstawka">     <td>stawka</td>     <td>12</td> </tr>  <tr id="rowgodziny">     <td>godziny</td>     <td>50</td> </tr>  <tr id="rowpensja">     <td>pensja</td>     <td>-</td> </tr>  <tr id="rownetto">     <td>pensja netto</td>     <td>x</td> </tr>   </table> 

if can change html, try using classes determine cells contains number calculated:

<table id="tabela">     <tr id="rowstawka">         <td>stawka</td>         <td class="num">12</td>     </tr>     <tr id="rowgodziny">         <td>godziny</td>         <td class="num">50</td>     </tr>     <tr id="rowpensja">         <td>pensja</td>         <td>-</td>     </tr>     <tr id="rownetto">         <td>pensja netto</td>         <td id="result">x</td>     </tr> </table> 

then use simple snippet make magic:

var numbers = document.queryselectorall(".num"); var total = 1;  (var = 0; < numbers.length; i++) {     total*= number(numbers[i].innertext); }  document.getelementbyid("result").innertext = total; 

fiddle