json

json格式细节1

JSON（JavaScript Object  Notation）一种简单的数据格式，比xml更轻巧。JSON是JavaScript原生格式，这意味着在JavaScript中处理JSON数据不需要任何特殊的API或工具包。
JSON的规则很简单：对象是一个无序的“‘名称/值’对”集合。一个对象以“{”（左括号）开始，“}”（右括号）结束。每个“名称”后跟一个“:”（冒号）；“‘名称/值’对”之间使用“,”（逗号）分隔。
   规则如下:
       1）映射用冒号（“：”）表示。名称:值
       2）并列的数据之间用逗号（“，”）分隔。名称1:值1,名称2:值2
       3） 映射的集合（对象）用大括号（“{}”）表示。{名称1:值1,名称2:值2}
       4） 并列数据的集合（数组）用方括号(“[]”)表示。
         [
           {名称1:值,名称2:值2},
           {名称1:值,名称2:值2}
         ]
      5)  元素值可具有的类型：string, number, object, array, true, false, null

json格式细节2

JSON 用冒号(而不是等号)来赋值。每一条赋值语句用逗号分开。整个对象用大括号封装起来。可用大括号分级嵌套数据。
对象描述中存储的数据可以是字符串，数字或者布尔值。对象描述也可存储函数，那就是对象的方法。

json格式其它解析案例

例子一:

<script language="JavaScript"> 
     var people ={"firstName": "Brett", "lastName":"McLaughlin", 
                                                        "email": "[email protected]" };
     alert(people.firstName); 
     alert(people.lastName); 
     alert(people.email); 
</script>

例子二:

<script language="JavaScript"> 
      var people =[ 
                     {"firstName": "Brett","email": "[email protected]" }, 
                     {"firstName": "Mary","email": "[email protected]" } 
                ]; 
    alert(people[0].firstName); 
    alert(people[0].email); 
    alert(people[1].firstName); 
    alert(people[1].email); 
</script>

例子三:

<script language="JavaScript"> 
     var people ={ 
            "programmers": 
              [ 
                {"firstName": "Brett", "email": "[email protected]" }, 
                {"firstName": "Jason", "email": "[email protected]" } 
              ] 
}; 
window.alert(people.programmers[0].firstName); 
window.alert(people.programmers[1].email); 
</script>

例子四:

<script language="JavaScript"> 
    var people ={ 
            "programmers": [ 
            { "firstName": "Brett", "email": "[email protected]" }, 
            { "firstName": "Jason",  "email": "[email protected]" }, 
            { "firstName": "Elliotte", "lastName":"Harold", "email": "[email protected]" }
           ], 
          "authors": [ 
            { "firstName": "Isaac",  "genre": "science fiction" }, 
            { "firstName": "Tad", "genre": "fantasy" }, 
            { "firstName": "Frank",  "genre": "christian fiction" } 
           ], 
          "musicians": [ 
            { "firstName": "Eric",  "instrument": "guitar" }, 
            { "firstName": "Sergei", "instrument": "piano" } 
           ]}; 
    window.alert(people.programmers[1].firstName); 
    window.alert(people.musicians[1].instrument); 
</script>

例子五：

<script language="JavaScript"> 
      var people ={ 
             "username":"mary", 
             "age":"20", 
             "info":{"tel":"1234566","celltelphone":788666}, 
             "address":[ 
                     {"city":"beijing","code":"1000022"}, 
                     {"city":"shanghai","code":"2210444"} 
              ] 
        };
      window.alert(people.username); 
      window.alert(people.info.tel); 
      window.alert(people.address[0].city); 
</script>