JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="decimalPt"> <br />

JavaScript

$('.decimalPt').keypress(function(evt) {
  evt = (evt) ? evt : window.event;
  var charCode = (evt.which) ? evt.which : evt.keyCode;
  if (charCode == 8 || charCode == 37) {
    return true;
  } else if (charCode == 46 && $(this).val().indexOf('.') != -1) {
    return false;
  } else if (charCode > 31 && charCode != 46 && (charCode < 48 || charCode > 57)) {
    return false;
  }
  return true;
});