以下はJSON文字列です。

JSON文字列

{
    "name": "mkyong",
    "age": 30,
    "address": {
        "streetAddress": "88 8nd Street",
        "city": "New York"
    },
    "phoneNumber":[        {
            "type": "home",
            "number": "111 111-1111"
        },
        {
            "type": "fax",
            "number": "222 222-2222"
        }
   ]}

JavaScriptでJSONオブジェクトにアクセスするには、JSON.parse()で解析し、「。」または「[]」でアクセスします。

JavaScript

<script>
       var data = '{"name": "mkyong","age": 30,"address": {"streetAddress": "88 8nd Street","city": "New York"},"phoneNumber":[{"type": "home","number": "111 111-1111"},{"type": "fax","number": "222 222-2222"}]}';

    var json = JSON.parse(data);

    alert(json["name"]);//mkyong
    alert(json.name);//mkyong

    alert(json.address.streetAddress);//88 8nd Street
    alert(json["address"].city);//New York

    alert(json.phoneNumber[0].number);//111 111-1111
    alert(json.phoneNumber[1].type);//fax

    alert(json.phoneNumber.number);//undefined
</script>