php判断json格式是否正确的方法

function data($value) {
    $res = json_decode($value, true);    
    $error = json_last_error();    
    if (!empty($error)) {        echo "<pre>";
        print_r($value);        echo "</pre>";
    }    return $res;
}

<?php
     if (!function_exists('json_last_error_msg')) {         function json_last_error_msg() {
             static $ERRORS = array(
                 JSON_ERROR_NONE => 'No error',
                 JSON_ERROR_DEPTH => 'Maximum stack depth exceeded',
                 JSON_ERROR_STATE_MISMATCH => 'State mismatch (invalid or malformed JSON)',
                 JSON_ERROR_CTRL_CHAR => 'Control character error, possibly incorrectly encoded',
                 JSON_ERROR_SYNTAX => 'Syntax error',
                 JSON_ERROR_UTF8 => 'Malformed UTF-8 characters, possibly incorrectly encoded'
             );             $error = json_last_error();             return isset($ERRORS[$error]) ? $ERRORS[$error] : 'Unknown error';
         }
     }

$array = array('key' => 'value', 'test' => array('测试一下', 2, 3));echo "<pre>";
print_r(json_encode($array, JSON_UNESCAPED_UNICODE));echo "</pre>";exit;

//将汉字，特殊字符原样变成json数据function ch_json_encode($data) {
    $ret = ch_urlencode($data);    $ret = json_encode($ret);    return '\'' . addslashes(urldecode($ret)) . '\'';
}//汉字，特殊字符变可读懂的字符串主程序function ch_urlencode($data) {
    if (is_array($data) || is_object($data)) {        foreach ($data as $k => $v) {            if (is_scalar($v)) {                if (is_array($data)) {                    $data[$k] = urlencode($v);
                } else if (is_object($data)) {                    $data->$k = urlencode($v);
                }
            } else if (is_array($data)) {                $data[$k] = ch_urlencode($v); // 递归调用该函数
            } else if (is_object($data)) {                $data->$k = ch_urlencode($v);
            }
        }
    }    return $data;
}

$output = str_replace("'", '"', $output);

$output = iconv('gbk', 'utf8', $output);

preg_replace('/,\s*([\]}])/m', '$1', $output)

$jsonstr = '

{"succ":true,"data":{"id":"31","keywords":"","description":"","jianjie":"       ","jianjie_short":"bb","nav":"ccc","deleted":"0","url":"http:\/\/travel.sina.com.cn\/beijing\/

"}}';//$ret=preg_replace("/\t/", " ", $ret);  

//$jsonstr = preg_replace("/\n/", ' ', $jsonstr);$jsonstr = str_replace("\n", ' ', $jsonstr);//print_r($jsonstr);exit;//$jsonstr = str_replace ('\n','', $jsonstr);$jd = json_decode($jsonstr,true);$errorinfo = json_last_error();//print_r(JSON_ERROR_DEPTH);

print_r($jd);