var allCookies = document.cookie;

document.cookie = updatedCookie;

document.cookie = "fontSize=14";
document.cookie = "fontSize=16";
document.cookie = "fontColor=black";

document.cookie; // fontSize=16;fontColor=black

Set-Cookie: value[; expires=date][; domain=domain][; path=path][; secure]

var cookieUtil = {
  // 设置cookie
  setItem: function(name, value, days) {
    var date=new Date();
    date.setDate(date.getDate()+days);
    document.cookie=name+'='+value+';expires='+date;
  },

  // 获取cookie
  getItem: function(name) {
     var arr=document.cookie.replace(/\s/g, "").split(';');
     for(var i=0;i<arr.length;i++) {
       var tempArr=arr[i].split('=');
       if(tempArr[0]==name) {
        return decodeURIComponent(tempArr[1]);
       }
     }
     return '';
  },

  // 删除cookie
  removeItem: function(name) {
    this.setItem(name,'1', -1);
  },

  // 检查是否含有某cookie
  hasItem: function(name) {
    return (new RegExp("(?:^|;\\s*)" + encodeURIComponent(name).replace(/[\-\.\+\*]/g, "\\$&") + "\\s*\\=")).test(document.cookie);
  },

  // 获取全部的cookie列表
  getAllItems: function() {
    var cookieArr = document.cookie.replace(/((?:^|\s*;)[^\=]+)(?=;|$)|^\s*|\s*(?:\=[^;]*)?(?:\1|$)/g, "").split(/\s*(?:\=[^;]*)?;\s*/);
    for (var nIdx = 0; nIdx < cookieArr.length; nIdx++) { cookieArr[nIdx] = decodeURIComponent(cookieArr[nIdx]); }
    return cookieArr;
  }
};