JSFiddle - React, Tailwind, and code Playground

HTML

<div id="log"/>

JavaScript

var log=document.getElementById('log');

function isNumber(n) {
  return !isNaN(parseFloat(n)) && isFinite(n);
}
function isNumeric(val) {
    return !isNaN(+val) && isFinite(val);
}

var value = '  23.1 ';

var object = {name: 'Not always a number', valueOf: function(){ return 42 }};

log.innerHTML = 
    '&apos;' + value + '&apos; isNumeric:' + isNumeric(value) + ' isNumber: ' + isNumber(value) + '<br/>&apos;' +
    object + '&apos; isNumeric:' + isNumeric(object) + ' isNumber: ' + isNumber(object);