JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="nombre" value="1.0"/>
<input type="button" value="Test" onclick="Tester();"/>

JavaScript

function Tester()
{
	if( isNaN($("nombre").val()) )
  {
  	alert("OK");
  }
  else
  {
  	alert("NOK");
  }
}