how to read json string in javascript code example

Example 1: javascript parse json

var jsonPerson = '{"first_name":"billy", "age":23}';
var personObject = JSON.parse(jsonPerson); //parse json string into JS object

Example 2: json to array javascript

var json_data = {"2013-01-21":1,"2013-01-22":7};
var result = [];

for(var i in json_data)
    result.push([i, json_data [i]]);


var data = new google.visualization.DataTable();
data.addColumn('string', 'Topping');
data.addColumn('number', 'Slices');
data.addRows(result);