js生成json数组

var datas=[];

var data = {};
data["id"] = 1;
data["name"] = "test" + 1;
data["age"] = 1 * 2;
datas.push(data);
var jsonString = JSON.stringify(datas);  //[{"id":1,"name":"test1","age":2}]
msg.innerHTML=jsonString;
var epc=eval("("+jsonString+")");
alert(epc[0].id);