JavaScript之Json的使用

Json字符串转JavaScript对象

 1 <html>
 2 <body>
 3 <h3>通过 JSON 字符串来创建对象</h3>
 4 <p>
 5 First Name: <span id="fname"></span><br /> 
 6 Last Name: <span id="lname"></span><br /> 
 7 </p> 
 8 <script type="text/javascript">
 9 var txt = '{"employees":[' +
10 '{"firstName":"Bill","lastName":"Gates" },' +
11 '{"firstName":"George","lastName":"Bush" },' +
12 '{"firstName":"Thomas","lastName":"Carter" }]}';
13 
14 obj = JSON.parse(txt);
15 
16 document.getElementById("fname").innerHTML=obj.employees[1].firstName 
17 document.getElementById("lname").innerHTML=obj.employees[1].lastName 
18 </script>
19 </body>
20 </html>

注意：

eval() 函数使用的是 JavaScript 编译器，可解析 JSON 文本，然后生成 JavaScript 对象。必须把文本包围在括号中，这样才能避免语法错误：

var obj = eval ("(" + txt + ")");

Json字符串转JavaScript对象2

 1 <html>
 2 <body>
 3 <h3>通过 JSON 字符串来创建对象</h3>
 4 <p>
 5 First Name: <span id="fname"></span><br /> 
 6 Last Name: <span id="lname"></span><br /> 
 7 </p> 
 8 <script type="text/javascript">
 9 var txt = '{"employees":[' +
10 '{"firstName":"Bill","lastName":"Gates" },' +
11 '{"firstName":"George","lastName":"Bush" },' +
12 '{"firstName":"Thomas","lastName":"Carter" }]}';
13 
14 var obj = eval ("(" + txt + ")");
15 
16 document.getElementById("fname").innerHTML=obj.employees[1].firstName 
17 document.getElementById("lname").innerHTML=obj.employees[1].lastName 
18 </script>
19 </body>
20 </html>

JavaScript对象转JSON字符串

 1 </div>
 2 <h3>JavaScript对象转换为Json字符串</h3>
 3 <p>
 4     all: <span id="all3"></span><br/>
 5 </p>
 6 <script type="text/javascript">
 7     var txt = '{"employees":[' +
 8         '{"firstName":"Bill","lastName":"Gates" },' +
 9         '{"firstName":"George2","lastName":"Bush2" },' +
10         '{"firstName":"Thomas","lastName":"Carter" }]}';
11 
12     var obj3 = eval("(" + txt + ")");
13     document.getElementById("all3").innerHTML = JSON.stringify(obj3);
14 </script>
15 <div>

来自：http://www.w3school.com.cn/json/json_eval.asp