jQuery基于json与cookie实现购物车办法【jquery】

/*添加商品及数量到购物车cookie中,返回当前商品在cookie中的总数*/function AddToShoppingCar(id, num) {  var _num = 1;  if (num != undefined)    _num = num;  var totalNum = _num; //总数默认为传入参数  var cookieSet = { expires: 7, path: '/' }; //设置cookie路径的//  $.cookie(cookieProductID, null, cookieSet);//清除Cookie  var jsonStr = "[{'ProductID':'" + id + "','Num':'" + _num + "'}]"; //构造json字符串,id是商品id  num是这个商品的数量  if ($.cookie(cookieProductID) == null) {    $.cookie(cookieProductID, jsonStr, cookieSet); //如果没有这个cookie就设置他  }  else {    var jsonObj = eval('(' + $.cookie(cookieProductID) + ')'); //如果有，把json字符串转换成对象    var findProduct = false;//是否找到产品ID,找到则为TRUE,否则为FALSH    for (var obj in jsonObj) {      if (jsonObj[obj].ProductID == id) {        jsonObj[obj].Num = Number(jsonObj[obj].Num) + _num;        totalNum = jsonObj[obj].Num;        findProduct = true;        break;      }    }    if (findProduct == false) { //没找到,则添加      jsonObj[jsonObj.length] = new Object();      jsonObj[jsonObj.length - 1].ProductID = id;      jsonObj[jsonObj.length - 1].Num = num;    }    $.cookie(cookieProductID, JSON.stringify(jsonObj), cookieSet); //写入coockie  JSON需要json2.js支持  }  return totalNum;  //  alert($.cookie(cookieProductID));}

//以下为cookie插件代码jQuery.cookie = function(name, value, options) {  if (typeof value != 'undefined') { // name and value given, set cookie    options = options || {};    if (value === null) {      value = '';      options.expires = -1;    }    var expires = '';    if (options.expires && (typeof options.expires == 'number' || options.expires.toUTCString)) {      var date;      if (typeof options.expires == 'number') {        date = new Date();        date.setTime(date.getTime() + (options.expires * 24 * 60 * 60 * 1000));      } else {        date = options.expires;      }      expires = '; expires=' + date.toUTCString(); // use expires attribute, max-age is not supported by IE    }    var path = options.path ? '; path=' + options.path : '';    var domain = options.domain ? '; domain=' + options.domain : '';    var secure = options.secure ? '; secure' : '';    document.cookie = [name, '=', encodeURIComponent(value), expires, path, domain, secure].join('');  } else { // only name given, get cookie    var cookieValue = null;    if (document.cookie && document.cookie != '') {      var cookies = document.cookie.split(';');      for (var i = 0; i < cookies.length; i++) {        var cookie = jQuery.trim(cookies[i]);        // Does this cookie string begin with the name we want?        if (cookie.substring(0, name.length + 1) == (name + '=')) {          cookieValue = decodeURIComponent(cookie.substring(name.length + 1));          break;        }      }    }    return cookieValue;  }};