Reading cookie expiration date

Question

Is it possible to read cookie expiration date using JavaScript?

If yes, how? If not, is there a source I can look at?

Answer 1

There is a work-around to OP's question if you also control the setting of the cookies. I do it like this:

function setCookie(name, value, expiryInDays) {
  const d = new Date();
  d.setTime(d.getTime() + expiryInDays * 24 * 60 * 60 * 1000);

  document.cookie = `${name}=${value}_${d.toUTCString()};expires=${d.toUTCString()}`;
}

function showCookies() {
  if (document.cookie.length !== 0) {
    const allCookies = document.cookie.split(/;\s*/);
    const wrapper = document.getElementById('allCookies');

    wrapper.innerHTML = allCookies.reduce((html, cookie, index) => {
      const cookieParts = cookie.split('=');
      const cookieValueParts = cookieParts[1].split('_');
      const cookieHtml = [
        `${index + 1}`,
        `Cookie name: ${cookieParts[0]}`,
        `Cookie value: ${cookieValueParts[0]}`,
        `Expires: ${cookieValueParts[1] || 'unknown'}`
      ].join('
');
      return html + `
${cookieHtml}
`;
    }, '');
  }
}

Show me the cookies!