int json_last_error ( void )

<?php
// 一個(gè)有效的 json 字符串
$json[] = '{"Organization": "PHP Documentation Team"}';
 
// 一個(gè)無(wú)效的 json 字符串會(huì)導(dǎo)致一個(gè)語(yǔ)法錯(cuò)誤，在這個(gè)例子里我們使用 ' 代替了 " 作為引號(hào)
$json[] = "{'Organization': 'PHP Documentation Team'}";
 
 
foreach ($json as $string) {
    echo 'Decoding: ' . $string;
    json_decode($string);
 
    switch (json_last_error()) {
        case JSON_ERROR_NONE:
            echo ' - No errors';
        break;
        case JSON_ERROR_DEPTH:
            echo ' - Maximum stack depth exceeded';
        break;
        case JSON_ERROR_STATE_MISMATCH:
            echo ' - Underflow or the modes mismatch';
        break;
        case JSON_ERROR_CTRL_CHAR:
            echo ' - Unexpected control character found';
        break;
        case JSON_ERROR_SYNTAX:
           echo ' - Syntax error, malformed JSON';
        break;
        case JSON_ERROR_UTF8:
            echo ' - Malformed UTF-8 characters, possibly incorrectly encoded';
        break;
        default:
            echo ' - Unknown error';
        break;
    }
 
    echo PHP_EOL;
}