As you can read in this topic:
You combine the use jQuery.cookie plugin and JSON and solve your problem.
When you want to store an array, you create an array in JS and use JSON.stringify to transform it into an string and stored with $.cookie('name', 'array_string')
var myAry = [1, 2, 3];
$.cookie('name', JSON.stringify(myAry));
When you want to retrive the array inside the cookie, you use $.cookie('name') to retrive the cookie value and use JSON.parse to retrive the array from the string.
var storedAry = JSON.parse($.cookie('name'));
//storedAry -> [1, 2, 3]