1.一次访问一个嵌套内容值
var myObj, x;

myObj = {

    "name":"网站",

    "num":,

    "sites":[ "Google", "Runoob", "Taobao" ]

}

x = myObj.sites[];

document.getElementById("demo").innerHTML = x;
输出内容：
Google

2.改进：遍历嵌套内容值

var myObj, x;
   myObj = {
   "name":"网站",
    "num":3,
    "sites":[ "Google", "Runoob", "Taobao" ]
    }

x = myObj.sites[0];

for(x in myObj.sites){
    document.getElementById("demo").innerHTML += myObj.sites[x]+ "<br>";

  }

输出内容：
Google
Runoob
Taobao

<p>循环内嵌数组：</p>

<p id="demo"></p>

<script>

var myObj, i, j, x = "";

myObj = {

    "name":"网站",

    "num":,

    "sites": [

        { "name":"Google", "info":[ "Android", "Google 搜索", "Google 翻译" ] },

        { "name":"Runoob", "info":[ "我是一个菜鸟", "菜鸟的工具", "菜鸟的微信" ] },

        { "name":"Taobao", "info":[ "淘宝", "京东" ] }

    ]

}

for (i in myObj.sites) {

    x += "<h1>" + myObj.sites[i].name + "</h1>";

    for (j in myObj.sites[i].info) {

        x += myObj.sites[i].info[j] + "<br>";

    }

}

document.getElementById("demo").innerHTML = x;