JavaWeb22.2【Ajax&Json：Json语法】

 

 

 

 

 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title>5-json语法-定义和取值</title>
 6     <script>
 7         //1 基本格式
 8         var person = {"name":"zhangsan", age:23, 'gender':true}; //键名注意不要这样写，格式要统一，方便阅读
 9         // alert(person); //[object Object]
10        /* var name = person.name;
11         var name = person["name"];
12         alert(name); //zhangsan*/
13 
14 
15         //2 嵌套格式{}-->[]
16         var persons = {
17             "person":[
18                 {"name":"zhangsan", "age":23, "gender":true},
19                 {"name":"李四", "age":16, "gender":false},
20                 {"name":"WW", "age":22, "gender":true}
21             ]
22         };
23         // alert(persons); //[object Object]
24         /*var name1 = persons.person[1].name;
25         alert(name1); //李四*/
26 
27 
28         //3 嵌套格式[]-->{}
29         var ps = [
30             {"name":"zhangsan", "age":23, "gender":true},
31             {"name":"李四", "age":16, "gender":false},
32             {"name":"WW", "age":22, "gender":true}
33         ];
34         // alert(ps); //[object Object],[object Object],[object Object]
35         /*var name2 = ps[2].name;
36         alert(name2); //WW*/
37 
38     </script>
39 </head>
40 <body>
41 
42 </body>
43 </html>
 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title>5-json语法-遍历</title>
 6     <script>
 7         var person = {"name":"zhangsan", "age":23, "gender":true};
 8 
 9         //利用for...in...循环获取person对象中的键和值
10         /*for (var key in person){
11             // alert(key); //注意key默认是字符串格式
12             // alert(key + ":" + person.key); //这样的方式获取不行，因为相当于person."name"，而不是person.name
13             alert(key + ":" + person[key]);
14         }*/
15 
16 
17         var ps = [
18             {"name":"zhangsan", "age":23, "gender":true},
19             {"name":"李四", "age":16, "gender":false},
20             {"name":"WW", "age":22, "gender":true}
21         ];
22 
23         //利用双层嵌套循环遍历ps
24         for (var i=0; i<ps.length; i++){
25             var p = ps[i];
26             for (var key in p){
27                 alert(key + ":" + p[key]);
28             }
29         }
30 
31     </script>
32 </head>
33 <body>
34 
35 </body>
36 </html>

 

posted @ 2021-07-08 17:37  yub4by  阅读(38)  评论(0)    收藏  举报