js 讀取JSON值

{
"AreaMax":
 
{
    "schema":[
        {"name":"AREA","type":"string"},
        {"name":"ADCD","type":"string"},
        {"name":"VAL","type":"decimal"},
        {"name":"STNM","type":"string"},
        {"name":"row","type":"long"}
    ],
    "data":[
     
        {"AREA":"洪洋鄉","ADCD":"350123201000000","VAL":"2.0","STNM":"厝坪-氣象","row":"1"},
        {"AREA":"霍口畲族鄉","ADCD":"350123203000000","VAL":"1.0","STNM":"斌溪水庫-防汛","row":"1"},
        {"AREA":"白塔鄉","ADCD":"350123200000000","VAL":"1.0","STNM":"蘇區水庫-水文","row":"1"},
        {"AREA":"鳳山鎮","ADCD":"350123100000000","VAL":"1.0","STNM":"羅源-防汛","row":"1"},
        {"AREA":"松山鎮","ADCD":"350123101000000","VAL":"1.0","STNM":"松山圍墾-防汛","row":"1"},
        {"AREA":"西蘭鄉","ADCD":"350123202000000","VAL":"0.0","STNM":"洋坪-防汛","row":"1"},
        {"AREA":"鑒江鎮","ADCD":"350123105000000","VAL":"0.0","STNM":"碧里-氣象","row":"1"}
    ]
}
,"AreaAvg":
{
"data":[
     
        {"AREA":"洪洋鄉","AVGVAL":"1"},
        {"AREA":"霍口畲族鄉","AVGVAL":"0.5"},
        {"AREA":"白塔鄉","AVGVAL":"0.5"},
        {"AREA":"鳳山鎮","AVGVAL":"0.5"},
        {"AREA":"松山鎮","AVGVAL":"1"},
        {"AREA":"西蘭鄉","AVGVAL":"0.0"},
        {"AREA":"鑒江鎮","AVGVAL":"0.0"}
    ]
}
}
 
以上是數據源
javascript 獲取jason值
  var jsonData;
$.ajax({
                    type: "Get",   //請求的方法
                    url: "../public/dataaccess/rain/RainAreaMaxDataProvider.ashx?adomParameter=" + Math.floor(Math.random() * 1000 + 1), //要傳遞參數使用Ajax進行處理的類名稱
                    dataType: "text",   //返回的數據類型
                    global: false,  //Ajax的范圍
                    async: false,   //異步執行
                    //成功情況下的處理
                    success: function (strReult) {

                       jsonData=eval("("+strReult+")");              
                      // var f= jsonData.AreaMax.data[0].AREA;
                    }, //失敗情況下的處理
                    error: function () {
                        alert("Ajax請求數據失敗!");
                    }
             });
            //循環讀取
            for(var i=0;i<jsonData.AreaMax.data.length;i++){
                       rainAreaMaxHtml+=jsonData.AreaMax.data[i].AREA+jsonData.AreaMax.data[i].STNM+jsonData.AreaMax.data[i].VAL;
             }