$('select.dates').change(function() {
$(this).closest('tr').find('input.numValue').val($(this.options[this.selectedIndex]).attr('data-value'));
});
function addnewrow()
{
var n=($('.table tr').length-0)+1;
var tr = '<tr>'+
'<td><select class="dates"><option value="select" data-value="">select</option><option value="value1" data-value="500">value1</option><option value="value2" data-value="300">value2</option><option value="value3" data-value="250">value3</option></select>'+
'<td><input type="text" class="numValue" value="" /></td>'+
'</tr>';
$('.detail').append(tr);
}
$('#add').click(function()
{
addnewrow();
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<table class="table">
<thead>
<th><input type="button" value="+" id="add" class="btnbtn-primary"></th>
<th>select</th>
<th>value</th>
</thead>
<tbody class="detail">
<tr class="row">
<td>
<select class="dates">
<option value="select" data-value="">select</option>
<option value="value1" data-value="500">value1</option>
<option value="value2" data-value="600">value2</option>
<option value="value3" data-value="900">value3</option>
</select>
</td>
<td><input type="text" class="numValue" value="" /></td>
</tr>
<tr>
<td>
<select class="dates">
<option value="select" data-value="">select</option>
<option value="value1" data-value="500">value1</option>
<option value="value2" data-value="300">value2</option>
<option value="value3" data-value="250">value3</option>
</select>
</td>
<td>
<input type="text" class="numValue" value="" />
</td>
</tr>
<tr>
<td>
<select class="dates">
<option value="select" data-value="">select</option>
<option value="value1" data-value="500">value1</option>
<option value="value2" data-value="300">value2</option>
<option value="value3" data-value="250">value3</option>
</select>
</td>
<td>
<input type="text" class="numValue" value="" />
</td>
</tr>
</tbody>
</table>
$('select.dates').change(function() {
$(this).next('input.numValue').val($(this.options[this.selectedIndex]).attr('data-value'));
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<table class="table">
<thead>
<th>select</th>
<th>value</th>
</thead>
<tbody>
<tr class="row">
<td>
<select class="dates">
<option value="1/1/11" data-value="num1">1/1/11</option>
<option value="1/2/11" data-value="num2">1/2/11</option>
<option value="1/3/11" data-value="num3">1/3/11</option>
</select>
</td>
<td><input type="text" class="numValue" value="" /></td>
</tr>
<tr>
<td>
<select class="dates">
<option value="1/1/11" data-value="num1">1/1/11</option>
<option value="1/2/11" data-value="num2">1/2/11</option>
<option value="1/3/11" data-value="num3">1/3/11</option>
</select>
</td>
<td>
<input type="text" class="numValue" value="" />
</td>
</tr>
</tbody>
</table>
my problem here that when i'm add new row with addnewrow() function
select function doesn't work with new row added but select function is
working prefect with static row why this is happen ? please help me i'm
still learning i want when i'm add new row with addnewrow() function select
input work thanks in advance .