jQuery get value of select onChange

I was under the impression that I could get the value of a select input by doing this $(this).val(); and applying the onchange parameter to the select field.

It would appear it only works if I reference the ID.

How do I do it using this.

Try this-

$('select').on('change', function() {
  alert( this.value );
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<select>
    <option value="1">One</option>
    <option value="2">Two</option>
</select>

You can also reference with onchange event-

function getval(sel)
{
    alert(sel.value);
}

<select onchange="getval(this);">
    <option value="1">One</option>
    <option value="2">Two</option>
</select>

I was under the impression that I could get the value of a select input by doing this $(this).val();

This works if you subscribe unobtrusively (which is the recommended approach):

$('#id_of_field').change(function() {
    // $(this).val() will work here
});

if you use onselect and mix markup with script you need to pass a reference to the current element:

onselect="foo(this);"

and then:

function foo(element) {
    // $(element).val() will give you what you are looking for
}

This is helped for me.

For select:

$('select_tags').on('change', function() {
    alert( $(this).find(":selected").val() );
});

For radio/checkbox:

$('radio_tags').on('change', function() {
    alert( $(this).find(":checked").val() );
});