PostSparrow

<script>
   $.each( obj, function( key, value ) {  
      alert( key + ": " + value );
   });
</script>

<script>
 $.each( [ "a", "b", "c" ], function( i, l ){
           alert( "Index #" + i + ": " + l );
     });
</script>

Run Each Loop in Table data

<table id="mainTable" border="2" width="100%">
	<thead >
		<th>Id</th>
		<th>Title</th>

		<th>Amount</th>
	</thead>
	<tbody>
		<tr>
			<td>01</td>
			<td>title 1</td>
			<td>199</td>
		</tr>
		<tr>
			<td>01</td>
			<td>title 2</td>
			<td>450</td>
		</tr>
		<tr>
			<td>01</td>
			<td>title 3</td>
			<td>230</td>
		</tr>
	</tbody>
</table>

<span id="total-value"></span>

<script type="text/javascript">
	var total = 0;
	$('#mainTable > tbody  > tr ').each(function(key, value) 
	{ 
		total = total + parseInt(value.cells[2].innerText);	
	});
	$('#total-value').text(total);	
</script>