Php/docs/function.json-last-error
json_last_error
(PHP 5 >= 5.3.0, PHP 7)
json_last_error — Returns the last error occurred
Description
json_last_error ( ) : int
Returns the last error (if any) occurred during the last JSON encoding/decoding,
which did not specify JSON_THROW_ON_ERROR.
Parameters
This function has no parameters.
Return Values
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 |
JSON_ERROR_RECURSION
|
One or more recursive references in the value to be encoded | PHP 5.5.0 |
JSON_ERROR_INF_OR_NAN
|
One or more | PHP 5.5.0 |
JSON_ERROR_UNSUPPORTED_TYPE
|
A value of a type that cannot be encoded was given | PHP 5.5.0 |
JSON_ERROR_INVALID_PROPERTY_NAME
|
A property name that cannot be encoded was given | PHP 7.0.0 |
JSON_ERROR_UTF16
|
Malformed UTF-16 characters, possibly incorrectly encoded | PHP 7.0.0 |
Examples
Example #1 json_last_error() example
<?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;}?>
The above example will output:
Decoding: {"Organization": "PHP Documentation Team"} - No errors
Decoding: {'Organization': 'PHP Documentation Team'} - Syntax error, malformed JSON
Example #2 json_last_error() with json_encode()
<?php// An invalid UTF8 sequence$text = "\xB1\x31";$json = json_encode($text);$error = json_last_error();var_dump($json, $error === JSON_ERROR_UTF8);?>
The above example will output:
string(4) "null" bool(true)
'Example #3 json_last_error() and JSON_THROW_ON_ERROR'
<?php// An invalid UTF8 sequence which causes JSON_ERROR_UTF8json_encode("\xB1\x31");// The following does not cause a JSON errorjson_encode('okay', JSON_THROW_ON_ERROR);// The global error state has not been changed by the former json_encode()var_dump(json_last_error() === JSON_ERROR_UTF8);?>
The above example will output:
bool(true)
See Also
- json_last_error_msg() - Returns the error string of the last json_encode() or json_decode() call
- json_decode() - Decodes a JSON string
- json_encode() - Returns the JSON representation of a value
