[javascript] Get the number of rows in a HTML table

I've browsed the Internet looking for an answer on this but I can't find a solution. I want to count the amount of rows my HTML table has in when a link button is pressed. Can someone help me out please?

This is what I have so far:

 $('#HypSelectAll').click(function () {
     var count = $('#gvPerformanceResult').children().length;
     for (i = 0; i < count; i++) {
        alert(i);
     }
 });

But some reason it returns 0 even though I have about 12 rows in my table? I've checked my ID name and it's correct.

Well it depends on what you have in your table.

its one of the following If you have only one table

var count = $('#gvPerformanceResult tr').length;

If you are concerned about sub tables but this wont work with tbody and thead (if you use them)

var count = $('#gvPerformanceResult>tr').length;

Where by this will work (but is quite frankly overkill.)

var count = $('#gvPerformanceResult>tbody>tr').length;

The following code assumes that your table has the ID 'MyTable'

<script language="JavaScript">
<!--
var oRows = document.getElementById('MyTable').getElementsByTagName('tr');
var iRowCount = oRows.length;

alert('Your table has ' + iRowCount + ' rows.');
//-->
</script>

Answer taken from : http://www.delphifaq.com/faq/f771.shtml, which is the first result on google for the query : "Get the number of rows in a HTML table" ;)

In the DOM, a tr element is (implicitly or explicitly) a child of tbody, thead, or tfoot, not a child of table (hence the 0 you got). So a general answer is:

var count = $('#gvPerformanceResult > * > tr').length;

This includes the rows of the table but excludes rows of any inner table.

var x = document.getElementById("myTable").rows.length;