php json_encode中文乱码如何解决

<?php
// json_encode() 保持中文方法详解

$arr['city'] = '北京';
$arr['name'] = 'weilong';

// 直接输出
// Res: {"city":"u5317u4eac","name":"weilong"}
echo json_encode($arr), "
";

#### 1. 加参数，PHP版本>=5.4
// Res: {"city":"北京","name":"weilong"}
echo json_encode($arr, JSON_UNESCAPED_UNICODE), "
";  // php >= 5.4

#### 2. 正则替换，json_encode后，正则将编码替换成中文
// Res: {"city":"北京","name":"weilong"}
echo preg_replace("#\u([0-9a-f]{4})#ie", "iconv('UCS-2BE', 'UTF-8', pack('H4', '\1'))", json_encode($arr)), "
";    // PHP 5.5 /e修饰符被弃用
echo preg_replace_callback("/\u([0-9a-f]{4})/i", function($match) {    // php >= 5.3 都可以
        return json_decode(""{$match[0]}"", true);
    }, json_encode($arr)), "
";

#### 3. urldecode()、urlencode()函数，不推荐
// Res1: null, Res2: {"city":"北京","name":"weilong"}
echo urldecode(json_encode(urlencode($arr))), "
";
$arr['city'] = urlencode($arr['city']);  // urlencode()参数必须是string
echo urldecode(json_encode($arr)), "
";


// 另外注意json_decode()参数区别。
$arr['city'] = '北京';
$arr['name'] = 'weilong';
$str = json_encode($arr);
$str2 = json_decode($str);
$str3 = json_decode($str, true);

print_r($str2); // object
/* Res:
stdClass Object
(
    [city] => 北京
    [name] => weilong
) */

print_r($str3); // array
/* Res:
Array
(
    [city] => 北京
    [name] => weilong
)
*/