JSFiddle - React, Tailwind, and code Playground
HTML
<input id="hours" type="number" class="form-control" style="width: 70px" placeholder="h" />
<input id="minutes" type="number" class="form-control" style="width: 70px" placeholder="m" />
<input class="yo" type="button" value="asd"/>
JavaScript
$(".yo").click(function(){
var hours = $('#hours').val();
var mintues = $('#minutes').val();
alert(hours+"."+mintues)
})