JSFiddle - React, Tailwind, and code Playground

by Samir Chaves

HTML

<input type="text"   onfocus="isNumber(this.value)" id="text" />

JavaScript

function isNumber(text){  
 valor = parseFloat(text);  
 if ((!isNaN(valor))==false)  
  {alert("Por favor, não digite ...");}  
  return true;  
 }