JSFiddle - React, Tailwind, and code Playground
by synz izynz
HTML
<select name='test' class='myclass' id='myid' data-n="q34234">
<option value="2" selected='selected'>2</option>
<option value="9999">lain-lain</option>
</select>
<input class='myinp'>
JavaScript
$.fn.test = function(){
var myval = $(this).val();
if(myval==='9999')
$('.myinp').show();
else
$('.myinp').hide();
};
$('#myid').on('change',function(){
$(this).test();
});
$('#myid').test();