PHP中生成json信息的方法

大家好，又见面了，我是全栈君。

 1 <?php
 2 
 3 //php中生成json信息
 4 //json_encode(数组/对象)
 5 
 6 $color = array('red','blue','green'); //【索引数组】
 7 echo json_encode($color),"<br />"; //["red","blue","green"]
 8 
 9 $animal = array('east'=>'tiger','north'=>'wolf','south'=>'monkey'); //【关联数组】
10 echo json_encode($animal),"<br />";//{"east":"tiger","north":"wolf","south":"monkey"}
11 
12 //【索引关联数组】
13 $animal2 = array('east'=>'tiger','north'=>'wolf','duck','south'=>'monkey');
14 echo json_encode($animal2),"<br />";//{"east":"tiger","north":"wolf","0":"duck","south":"monkey"}
15 
16 //[{},{},{}]
17 //{"weatherinfo":{"city":"北京","cityid":"101010100","temp":"9","WD":"南风","WS":"2级","SD":"26%","WSE":"2","time":"10:20","isRadar":"1","Radar":"JC_RADAR_AZ9010_JB","njd":"暂无实况","qy":"1014"}}
18 //{名称:[],名称:[],名称:[]}
19 
20 
21 //【对象生成json信息】
22 class Person{
23     public $addr = "beijing";
24     public $height = 170;
25     public function study(){
26         echo "study php";
27     }
28 }
29 $tom = new Person();
30 //只是对象的属性给生成json信息
31 echo json_encode($tom);//{"addr":"beijing","height":170}

1.json

json_encode(数组/对象)————>生成json信息，

json_decode(json信息); 反编码json信息

对json字符串信息进行反编码，变为当前语言可以识别的信息。

2. javascript接收处理json信息

通过eval()把接收的json字符串变成真实的对象信息

代码如下：

 1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
 2 <html>
 3     <head>
 4         <title>新建网页</title>
 5         <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 6         <meta name="description" content="" />
 7         <meta name="keywords" content="" />
 8 
 9         <script type="text/javascript">
10         function showweather(){
11             //利用ajax获得天气预报信息
12             //利用javascript+dom处理并显示天气信息
13             var xhr = new XMLHttpRequest();
14             xhr.onreadystatechange = function(){
15                 if(xhr.readyState==4){
16                     //alert(xhr.responseText);
17                     console.log(typeof xhr.responseText);//string
18                     //要把接收的“字符串”变为“对象”
19                     //'{"addr":"\u5317\u4eac","temp":"9-22","wind":"north4-5"}'
20                     eval("var info="+xhr.responseText);
21 
22                     var str = "地址："+info.addr+";温度:"+info.temp+";风向:"+info.wind;
23                     document.getElementById('result').innerHTML = str;
24                 }
25             }
26             xhr.open('get','./03.php');
27             xhr.send(null);
28         }
29         window.onload = function(){
30             showweather();
31         }
32         
33 //        //s字符串变为对象obj
34 //         var s = "{name:'tom',height:170}";
35 //        //"var obj="+"{name:'tom',height:170}"====>"var obj={name:'tom',height:170}"
36 //        //console.log("var obj="+s);  
37 //        eval("var obj="+s);
38 //        console.log(obj);//Object { name="tom", height=170}
39 
40         </script>
41 
42         <style type="text/css">
43         </style>
44     </head>
45     <body>
46         <h2>获得天气预报接口信息</h2>
47         <div id="result"></div>
48     </body>
49 </html>