First you should understand what the cookie is and how it's set. A cookie is a string that is stored on the user's computer to allow data to persist throughout the user's session. Cookies are often set by HTTP response headers, but they can also be set directly in the browser using JavaScript. To read the entire cookie string you can access document.cookie.

document.cookie

ps=31;_ssd3=P0-1415818163-1436218393727;favorite_animal=goat;_gaa=23.00334.....

What you'll likely see is a long string of semi-colon delineated key/value pairs.