jquery multidimenstional array in jquery

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Javascript

jQuery

hello there...
i have an array as follows

var data = '[{"Date":"3/5/2014 12:00:00 AM","DataValue":48.1380920410156},{"Date":"3/8/2014 12:00:00 AM","DataValue":0.0000000000000000000399998436},{"Date":"3/6/2014 12:00:00 AM","DataValue":0.0000000000000000000399998436},{"Date":"3/7/2014 12:00:00 AM","DataValue":0.0000000000000000000399998436},{"Date":"3/4/2014 12:00:00 AM","DataValue":0.0000000000000000000399998436}]';

and i need to access each element in jquery

$.each(data, function (index, item) {
                alert(item.Date);
            });

but it's not working properly.
plz help me