JSFiddle - React, Tailwind, and code Playground
HTML
<select name="object_0_status" id="id_object_0_status">
<option value="">---------</option>
<option value="1">Online</option>
<option value="2">Offline</option>
<option value="3">Unknown</option>
</select>
<select name="object_1_status" id="id_object_1_status">
<option value="">---------</option>
<option value="1">Online</option>
<option value="2">Offline</option>
<option value="3">Unknown</option>
</select>
<select name="object_2_status" id="id_object_2_status">
<option value="">---------</option>
<option value="1">Online</option>
<option value="2">Offline</option>
<option value="3">Unknown</option>
</select>
JavaScript
$('select[id$=_status]').change(function() {
getCount();
});
function getCount() {
alert($('select[id$=_status] option:selected[value="1"]').length);
}