(PHP 5 >= 5.3.0, PHP 7)
json_last_error — Returns the last error occurred
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.
This function has no parameters.
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 NAN or INF values in the value to be encoded | 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 |
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_UTF8
json_encode("\xB1\x31");
// The following does not cause a JSON error
json_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)
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Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.json-last-error.php