var CookieUtil = {
    // 设置cookie
    set : function (name, value, expires, domain, path, secure) {
      var cookieText = "";
      cookieText += encodeURIComponent(name) + "=" + encodeURIComponent(value);
      if (expires instanceof Date) {
        cookieText += "; expires=" + expires.toGMTString();
      }
      if (path) {
        cookieText += "; path=" + path;
      }
      if (domain) {
        cookieText += "; domain=" + domain;
      }
      if (secure) {
        cookieText += "; secure";
      }
      document.cookie = cookieText;
    },
    // name=value; expires=expiration_time; path=domain_path; domain=domain_name; secure
    // 获取cookie
    get : function (name) {
      var cookieName = encodeURIComponent(name) + "=",
        cookieStart = document.cookie.indexOf(cookieName),
        cookieValue = "";
      if (cookieStart > -1) {
        var cookieEnd = document.cookie.indexOf (";", cookieStart);
        if (cookieEnd == -1) {
          cookieEnd = document.cookie.length;
        }
        cookieValue = decodeURIComponent(document.cookie.substring(cookieStart + cookieName.length, cookieEnd));
      }
      return cookieValue; 
    },
    // 删除cookie
    unset : function (name, domain, path, secure) {
      this.set(name, "", Date(0), domain, path, secure);
    }
  };
  // 测试
  CookieUtil.set("name", "zhang");
  var name = CookieUtil.get("name");
  alert(name);  // zhang
  CookieUtil.unset("name");
  alert(CookieUtil.get("name")); // 空

  var SubCookieUtil = {
    /** 设置一条完整的cookie
    *  param name : 表示cookie的名称，必填
    *  param subCookies : 表示cookie的值，为一个对象，必填
    *  param expires : 表示cookie的过期时间，可以不填
    *  param domain : 表示cookie的域名，可以不填
    *  param path : 表示cookie的路径，可以不填
    *  param secure : 表示cookie的安全标志，可以不填
    *  eg : SubCookieUtil.setAll("info", { name : "zhang", age : 23});
    **/
    setAll : function (name, subCookies, expires, domain, path, secure) {
      var cookieText = "", subName, cookieParts = [];
      cookieText += encodeURIComponent(name) + "=";
      for(subName in subCookies) {
        cookieParts.push(encodeURIComponent(subName) + "=" + encodeURIComponent(subCookies[subName]));
      }
      if (cookieParts.length > 0) {
        cookieText += cookieParts.join("&");
        if (expires instanceof Date) {
          cookieText += "; expires=" + expires.toGMTString();
        }
        if (path) {
          cookieText += "; path=" + path;
        }
        if (domain) {
          cookieText += "; domain=" + domain;
        }
        if (secure) {
          cookieText += "; secure";
        }
      } else {
        cookieText += "; expires=" + Date(0).toGMTString();
      }
      document.cookie = cookieText;
    },
    /** 设置一条子cookie
    *  param name : 表示cookie的名称，必填
    *  param subName : 表示子cookie的名称，必填
    *  param value : 表示子cookie的值，必填
    *  param expires : 表示cookie的过期时间，可以不填
    *  param domain : 表示cookie的域名，可以不填
    *  param path : 表示cookie的路径，可以不填
    *  param secure : 表示cookie的安全标志，可以不填
    *  eg : SubCookieUtil.set("info", "sex", "boy");
    **/
    set : function (name, subName, value, expires, domain, path, secure) {
      var cookies = this.getAll(name) || {};
      cookies[subName] = value;
      this.setAll(name, cookies, expires, domain, path, secure);
    },
    /** 读取一条完整cookie
    *  param name : 表示cookie的名称，必填
    *  return : 一个cookie对象
    *  eg : SubCookieUtil.getAll("info");
    **/
    getAll : function (name) {
      var cookieName = encodeURIComponent(name) + "=",
        cookieStart = document.cookie.indexOf(cookieName),
        cookieValue = "", i, len, subCookies, parts, result = {};
      if (cookieStart > -1) {
        var cookieEnd = document.cookie.indexOf (";", cookieStart);
        if (cookieEnd == -1) {
          cookieEnd = document.cookie.length;
        }
        cookieValue = decodeURIComponent(document.cookie.substring(cookieStart + cookieName.length, cookieEnd));
        if (cookieValue.length > 0) {
          subCookies = cookieValue.split("&");
          for (i = 0, len = subCookies.length; i < len; i++) {
            parts = subCookies[i].split("=");
            result[decodeURIComponent(parts[0])] = decodeURIComponent(parts[1]);
          }
          return result;
        }
      }
      return null;
    },
    /** 获取一条子cookie的值
    *  param name : 表示cookie的名称，必填
    *  param subName : 表示子cookie的名称
    *  return : 一个子cookie的值
    *  eg : SubCookieUtil.get("info", "name");
    **/
    get : function (name, subName) {
      var cookies = this.getAll(name);
      if (cookies) {
        return cookies[subName];
      } else {
        return null;
      }
    }, 
    /** 删除一条完整cookie
    *  param name : 表示cookie的名称，必填
    *  param domain : 表示cookie的域名，可以不填
    *  param path : 表示cookie的路径，可以不填
    *  param secure : 表示cookie的安全标志，可以不填
    *  eg : SubCookieUtil.unsetAll("info");
    **/
    unsetAll : function (name, domain, path, secure) {
      this.setAll(name, "", Date(0).toGMTString(), domain, path, secure);
    },
    /** 删除一条子cookie
    *  param name : 表示cookie的名称，必填
    *  param subName : 表示子cookie的名称，必填
    *  param domain : 表示cookie的域名，可以不填
    *  param path : 表示cookie的路径，可以不填
    *  param secure : 表示cookie的安全标志，可以不填
    *  eg : SubCookieUtil.unset("info", "name");
    **/
    unset : function (name, subName, domain, path, secure) {
      var cookies = this.getAll(name);
      if (cookies) {
        delete cookies[subName];
        this.setAll(name, cookies, null, domain, path, secure);
      }
    }  
  };
  // 测试：
  var zhang = {
    name : "zhang",
    age : 23,
    height : "178cm",
    weight : "66kg"
  }
  // 设置一条完整的cookie
  SubCookieUtil.setAll("zhang", zhang);
  // 获取一条完整的cookie
  var zhang = SubCookieUtil.getAll("zhang");
  alert(zhang.weight);  // 66kg
  // 再为张添加一个子cookie
  SubCookieUtil.set("zhang", "sport", "basketball");
  // 获取子cookie
  alert(SubCookieUtil.get("zhang", "sport")); // basketball
  // 删除一条子cookie
  SubCookieUtil.unset("zhang", "age");
  alert(SubCookieUtil.get("zhang", "age"));  // undefined
  // 删除一条完整的cookie
  SubCookieUtil.unsetAll("zhang");
  alert(SubCookieUtil.getAll("zhang"));  // 报错，因为已经被删除