问题：有这样的字符串[{"CityId":18,"CityName":"西安","ProvinceId":27,"CityOrder":1},{"CityId":53,"CityName":"广州","ProvinceId":27,"CityOrder":1}]，用js转换成json对象。

解答：
var data;

var json='[{"CityId":18,"CityName":"西安","ProvinceId":27,"CityOrder":1},{"CityId":53,"CityName":"广州","ProvinceId":27,"CityOrder":1}]';

eval("data="+json);

alert(data);