JSFiddle - React, Tailwind, and code Playground
HTML
<input id='text' type='text' value="test"/>
<input id='datetime' type='datetime-local' />
<input type='button' id='button'/>
<script>
var datetimeval = $("#datetime").val();
var textval = $("#text").val();
$("#button").on('click', function(){
alert(datetimeval)
})
</script>