php json和字符串互转

记录一下：

<?php
 
//php反编码解析json信息
//json_decode(json字符串);
 
$city = array('shandong'=>'jinan','henan'=>'zhengzhou','hebei'=>'shijiazhuang');
$jn_city = json_encode($city);
 
//反编码json
$fan_city = json_decode($jn_city,false);//第二个参数false则返回object类型，false可以默认不写
var_dump($fan_city);//object(stdClass)#1 (3) { ["shandong"]=> string(5) "jinan" ["henan"]=> string(9) "zhengzhou" ["hebei"]=> string(12) "shijiazhuang" } 
echo "<br />";
 
$fan_city = json_decode($jn_city,true);//第二个参数true则返回array类型
var_dump($fan_city);//array(3) { ["shandong"]=> string(5) "jinan" ["henan"]=> string(9) "zhengzhou" ["hebei"]=> string(12) "shijiazhuang" }
 

<?php //json信息反编码 //不同php版本，对“纯json字符串”解析存在问题//使用双引号定义的json字符串反编码操作变为null//$jn = "{'name':'tom','age':'20','addr':'beijing'}";//$fan_jn = json_decode($jn,true);//var_dump($fan_jn);//NULL //使用单引号定义的json字符串反编码操作会成功$jn = '{"name":"tom","age":"20","addr":"beijing"}';$fan_jn = json_decode($jn,true);var_dump($fan_jn);