低版本的IE不支持JSON，JSON對象解析不是隨著javascript產生的，找到一段兼容常用的JSON.parse和JSON.stringify的代碼
if (!window.JSON) {
window.JSON = {
parse: function(jsonStr) {
return eval(‘(‘ + jsonStr + ‘)‘);
},
stringify: function(jsonObj) {
var result = ‘‘,
curVal;
if (jsonObj === null) {
return String(jsonObj);
}
switch (typeof jsonObj) {
case ‘number‘:
case ‘boolean‘:
return String(jsonObj);
case ‘string‘:
return ‘"‘ + jsonObj + ‘"‘;
case ‘undefined‘:
case ‘function‘:
return undefined;
}

switch (Object.prototype.toString.call(jsonObj)) {
case ‘[object Array]‘:
result += ‘[‘;
for (var i = 0, len = jsonObj.length; i < len; i++) {
curVal = JSON.stringify(jsonObj[i]);
result += (curVal === undefined ? null : curVal) + ",";
}
if (result !== ‘[‘) {
result = result.slice(0, -1);
}
result += ‘]‘;
return result;
case ‘[object Date]‘:
return ‘"‘ + (jsonObj.toJSON ? jsonObj.toJSON() : jsonObj.toString()) + ‘"‘;
case ‘[object RegExp]‘:
return "{}";
case ‘[object Object]‘:
result += ‘{‘;
for (i in jsonObj) {
if (jsonObj.hasOwnProperty(i)) {
curVal = JSON.stringify(jsonObj[i]);
if (curVal !== undefined) {
result += ‘"‘ + i + ‘":‘ +curVal + ‘,‘;
}
}
}
if (result !== ‘{‘) {
result = result.slice(0, -1);
}
result += ‘}‘;
return result;

case ‘[object String]‘:
return ‘"‘ + jsonObj.toString() + ‘"‘;
case ‘[object Number]‘:
case ‘[object Boolean]‘:
return jsonObj.toString();
}
}
};
}

IE低版本 JSON.parse 和stringify 的兼容 （IE8以下）