JSFiddle - React, Tailwind, and code Playground
by Felipe Zura
HTML
<input type="text" name="email" id="email">
JavaScript
function validaEmail(email){
var re = /^([a-zA-Z0-9_.-])+@(([a-zA-Z0-9-])+.)+([a-zA-Z0-9]{2,4})+$/;
if (!re.test(email)) { alert ("Dirección de correo inválida"); return false; } return true;
}
$("#email").on('blur',function(){validaEmail($(this).val());});