json_last_error
(PHP 5 >= 5.3.0)
json_last_error — Returns the last error occurred
说明
int json_last_error ( void )Returns the last error (if any) occurred during the last JSON encoding/decoding.
参数
此函数没有参数。
返回值
Returns an integer, the value can be one of the following constants:
| Constant | Meaning | Availability |
|---|---|---|
| JSON_ERROR_NONE | No error has occurred | |
| JSON_ERROR_DEPTH | The maximum stack depth has been exceeded | |
| JSON_ERROR_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 | PHP 5.3.3 |
范例
Example #1 json_last_error() example 以上例程会输出：
<?php
// A valid json string
$json[] = '{"Organization": "PHP Documentation Team"}';
// An invalid json string which will cause an syntax
// error, in this case we used ' instead of " for quotation
$json[] = "{'Organization': 'PHP Documentation Team'}";
foreach ($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;
}
?>
Decoding: {"Organization": "PHP Documentation Team"} - No errors
Decoding: {'Organization': 'PHP Documentation Team'} - Syntax error, malformed JSON
Example #2 json_last_error() with json_encode() 以上例程会输出：
<?php
// An invalid UTF8 sequence
$text = "xB1x31";
$json = json_encode($text);
$error = json_last_error();
var_dump($json, $error === JSON_ERROR_UTF8);
?>
string(4) "null"
bool(true)
参见
- json_decode() - 对 JSON 格式的字符串进行编码
- json_encode() - 对变量进行 JSON 编码
