<?php //php中生成json信息
//json_encode(数组/对象) $color = array('red','blue','green'); //【索引数组】
echo json_encode($color),"<br />"; //["red","blue","green"] $animal = array('east'=>'tiger','north'=>'wolf','south'=>'monkey'); //【关联数组】
echo json_encode($animal),"<br />";//{"east":"tiger","north":"wolf","south":"monkey"} //【索引关联数组】
$animal2 = array('east'=>'tiger','north'=>'wolf','duck','south'=>'monkey');
echo json_encode($animal2),"<br />";//{"east":"tiger","north":"wolf","0":"duck","south":"monkey"} //[{},{},{}]
//{"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"}}
//{名称:[],名称:[],名称:[]} //【对象生成json信息】
class Person{
public $addr = "beijing";
public $height = 170;
public function study(){
echo "study php";
}
}
$tom = new Person();
//只是对象的属性给生成json信息
echo json_encode($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：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<title>新建网页</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="description" content="" />
<meta name="keywords" content="" /> <script type="text/javascript">
function showweather(){
//利用ajax获得天气预报信息
//利用javascript+dom处理并显示天气信息
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function(){
if(xhr.readyState==4){
//alert(xhr.responseText);
console.log(typeof xhr.responseText);//string
//要把接收的“字符串”变为“对象”
//'{"addr":"\u5317\u4eac","temp":"9-22","wind":"north4-5"}'
eval("var info="+xhr.responseText); var str = "地址："+info.addr+";温度:"+info.temp+";风向:"+info.wind;
document.getElementById('result').innerHTML = str;
}
}
xhr.open('get','./03.php');
xhr.send(null);
}
window.onload = function(){
showweather();
} // //s字符串变为对象obj
// var s = "{name:'tom',height:170}";
// //"var obj="+"{name:'tom',height:170}"====>"var obj={name:'tom',height:170}"
// //console.log("var obj="+s);
// eval("var obj="+s);
// console.log(obj);//Object { name="tom", height=170} </script> <style type="text/css">
</style>
</head>
<body>
<h2>获得天气预报接口信息</h2>
<div id="result"></div>
</body>
</html>