PHP：JSON字符串转换为中文，中文转换为JSON字符串

/**
 * 中文转换为JSON字符串
 * @param $chinese_str 中文：可以包含中文字母数字
 * @return string
 */
function json_encode($chinese_str)
{
    $chinese_str = iconv('UTF-8', 'UCS-2', $chinese_str);
    $len = strlen($chinese_str) - 1;
    $str = '';
    for ($i = 0; $i < $len; $i = $i + 2)
    {
        $c1 = $chinese_str[$i];
        $c2 = $chinese_str[$i + 1];
        $unicode1=ord($c1);
        $unicode2=ord($c2);
        if ($unicode1)
        {    // 两个字节的文字
            $unicode1='\u'.base_convert($unicode1, 10, 16);
            $unicode2=base_convert($unicode2, 10, 16);
            if(in_array($unicode2,array('a','b','c','d','e','f'))){
                $unicode2='0'.$unicode2;
            }
            $str.=$unicode1.$unicode2;
        }else{
            $str.=$c2;
        }
    }
    return $str;
}
 
 
/**
 * JSON字符串转换为中文
 * @param $json_str JSON字符串
 * @return string
 */
function json_decode($json_str)
{
    // 转换编码，将JSON字符串转换成可以浏览的utf-8编码
    $pattern = '/([\w]+)|(\\\u([\w]{4}))/i';
    preg_match_all($pattern, $json_str, $matches);
    $chinese_str = '';
    if (!empty($matches))
    {
        $count=count($matches[0]);
        for ($j = 0; $j < $count; $j++)
        {
            $str = $matches[0][$j];
            if (strpos($str, '\\u') === 0)
            {
                $code = base_convert(substr($str, 2, 2), 16, 10);
                $code2 = base_convert(substr($str, 4), 16, 10);
                $c = chr($code).chr($code2);
                $c = iconv('UCS-2', 'UTF-8', $c);
                $chinese_str .= $c;
            }
            else
            {
                $chinese_str .= $str;
            }
        }
    }
    return $chinese_str;
}