Ejemplos de uso de cookies

<div id="contenedor" class="container ">
		<button id="poner">Pon cookie</button>
		<button id="obtener">Obtener cookie</button>
		<button id="eliminar">Eliminar cookie</button>
		<script src="js/test.js"></script>
	</div>

document.getElementById('poner').addEventListener('click', poner)
document.getElementById('obtener').addEventListener('click', obtener)
document.getElementById('eliminar').addEventListener('click', eliminar)

function poner () {
  setCookie('edad', 50, 10)
}
function obtener () {
  const edad = getCookie('edad')
  alert(edad)
}
function eliminar () {
  setCookie('edad', 50, -10)
}

function setCookie (cname, cvalue, exdays) {
  const d = new Date()
  d.setTime(d.getTime() + (exdays * 24 * 60 * 60 * 1000))
  const expires = 'expires=' + d.toUTCString()
  document.cookie = cname + '=' + cvalue + ';' + expires + ';path=/'
}

function getCookie (cname) {
  const name = cname + '='
  const decodedCookie = decodeURIComponent(document.cookie)
  const ca = decodedCookie.split(';')
  for (let i = 0; i < ca.length; i++) {
    let c = ca[i]
    while (c.charAt(0) == ' ') {
      c = c.substring(1)
    }
    if (c.indexOf(name) == 0) {
      return c.substring(name.length, c.length)
    }
  }
  return ''
}