Json技术使用代码示例

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:

 var people ={"firstName": "Brett", "lastName":"McLaughlin",   "email": "brett@newInstance.com" };
     alert(people.firstName);
     alert(people.lastName);
     alert(people.email);

例子二:

 var people =[
                     {"firstName": "Brett","email": "brett@newInstance.com" },
                     {"firstName": "Mary","email": "mary@newInstance.com" }
                ];
    alert(people[0].firstName);
    alert(people[0].email);
    alert(people[1].firstName);
    alert(people[1].email);

例子三:

  var people ={
            "programmers":
              [
                {"firstName": "Brett", "email": "brett@newInstance.com" },
                {"firstName": "Jason", "email": "jason@servlets.com" }
              ]
};
window.alert(people.programmers[0].firstName);
window.alert(people.programmers[1].email);

例子四:

 var people ={
            "programmers": [
            { "firstName": "Brett", "email": "brett@newInstance.com" },
            { "firstName": "Jason",  "email": "jason@servlets.com" },
            { "firstName": "Elliotte", "lastName":"Harold", "email": "elharo@macfaq.com" }
           ],
          "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);

例子五：

  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);