Модуль определяет перечисленные константы и открывает доступ к константам только тогда, когда модуль либо собрали в PHP, либо динамически загрузили во время исполнения кода.
Следующие константы указывают на тип ошибки, которую возвращает функция json_last_error() или которая хранится в свойстве code объекта исключения JsonException.
JSON_ERROR_NONE
(int)
JSON_ERROR_DEPTH
(int)
JSON_ERROR_STATE_MISMATCH
(int)
JSON_ERROR_CTRL_CHAR
(int)
JSON_ERROR_SYNTAX
(int)
JSON_ERROR_UTF8
(int)
JSON_ERROR_RECURSION
(int)
JSON_PARTIAL_OUTPUT_ON_ERROR, то
на месте рекурсивных ссылок будет выведен null.
JSON_ERROR_INF_OR_NAN
(int)
NAN,
либо INF.
Если была указана константа JSON_PARTIAL_OUTPUT_ON_ERROR,
то вместо указанных особых значений будет выведен 0.
JSON_ERROR_UNSUPPORTED_TYPE
(int)
JSON_PARTIAL_OUTPUT_ON_ERROR,
то вместо неподдерживаемого значения будет выводиться null.
JSON_ERROR_INVALID_PROPERTY_NAME
(int)
JSON_ERROR_UTF16
(int)
Можно комбинировать следующие константы для передачи в json_decode().
JSON_BIGINT_AS_STRING
(int)
JSON_OBJECT_AS_ARRAY
(int)
true.
Следующие константы можно комбинировать для использования в json_encode().
JSON_HEX_TAG
(int)
JSON_HEX_AMP
(int)
JSON_HEX_APOS
(int)
JSON_HEX_QUOT
(int)
JSON_FORCE_OBJECT
(int)
JSON_NUMERIC_CHECK
(int)
JSON_PRETTY_PRINT
(int)
JSON_UNESCAPED_SLASHES
(int)
/.
JSON_UNESCAPED_UNICODE
(int)
JSON_PARTIAL_OUTPUT_ON_ERROR
(int)
JSON_PRESERVE_ZERO_FRACTION
(int)
JSON_UNESCAPED_LINE_TERMINATORS
(int)
JSON_UNESCAPED_UNICODE. Поведение будет таким же,
какое оно было до PHP 7.1 без этой константы.
Доступна с PHP 7.1.0.
Следующие константы можно комбинировать для использования в json_decode() и json_encode().
JSON_INVALID_UTF8_IGNORE
(int)
JSON_INVALID_UTF8_SUBSTITUTE
(int)
JSON_THROW_ON_ERROR
(int)
JSON_PARTIAL_OUTPUT_ON_ERROR имеет приоритет над
JSON_THROW_ON_ERROR. Доступна с PHP 7.3.0.
JSON_ERROR_NON_BACKED_ENUM
(int)
To get a really clean json string use these three constants like so:
<?php
$array = ['€', 'http://example.com/some/cool/page', '337'];
$bad = json_encode($array);
$good = json_encode($array, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_NUMERIC_CHECK);
// $bad would be ["\u20ac","http:\/\/example.com\/some\/cool\/page","337"]
// $good would be ["€","http://example.com/some/cool/page",337]
?>If you curious of the numeric values of the constants, as of JSON 1.2.1, the constants have the following values (not that you should use the numbers directly):
JSON_HEX_TAG => 1
JSON_HEX_AMP => 2
JSON_HEX_APOS => 4
JSON_HEX_QUOT => 8
JSON_FORCE_OBJECT => 16
JSON_NUMERIC_CHECK => 32
JSON_UNESCAPED_SLASHES => 64
JSON_PRETTY_PRINT => 128
JSON_UNESCAPED_UNICODE => 256
JSON_ERROR_DEPTH => 1
JSON_ERROR_STATE_MISMATCH => 2
JSON_ERROR_CTRL_CHAR => 3
JSON_ERROR_SYNTAX => 4
JSON_ERROR_UTF8 => 5
JSON_OBJECT_AS_ARRAY => 1
JSON_BIGINT_AS_STRING => 2Be EXTREMELY cautious when using the code majid4466 at gmail dot com provided, or JSON_NUMERIC_CHECK in general.
For example, in php 7.4 and 8.1 with precision: 14 and serialize_precision: -1 we get:
<?php
$array = ['€', 55.6666666666666666, 'http://example.com/some/cool/page', '000337', '55.6666666666666666'];
echo $case1 = json_encode($array);
echo $case2 = json_encode($array, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES );
echo $case3 = json_encode($array, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_NUMERIC_CHECK);
["\u20ac",55.666666666666664,"http:\/\/example.com\/some\/cool\/page","000337","55.6666666666666666"]
// in $case1, both euro sign and the url change but we also lost a digit in our unquoted float (due to precision)
["€",55.666666666666664,"http://example.com/some/cool/page","000337","55.6666666666666666"]
// in $case2, both euro sign and the url stay exactly the same but we still lost a digit in our unquoted float (due to precision)
["€",55.666666666666664,"http://example.com/some/cool/page",337,55.666666666666664]
// in $case3, we once again keep euro sign and the url intact but this time not only our unquoted float lost a digit
// but the same happened to our quoted float and the number/string lost its leading zeros too
Also, note that in php 5.x you will probably get some different but equally wrong results as default values may be different and some functions have changed internally as well.In a multi-level array, JSON_FORCE_OBJECT will encode ALL nested numeric arrays as objects.
If your concern was ONLY the first-level array (e.g., to make it suitable as a MySQL JSON column), you could just cast your first-level array to object, e.g.:
<?php
$json = json_encode( (object) $array, JSON_PRESERVE_ZERO_FRACTION+JSON_UNESCAPED_UNICODE );
?>
Or, if you have large arrays and are concerned about the overhead of object casting, you could append a "null" value beyond the size of the array, which will force the array to become associative:
<?php
$beyond = count( $array ) + 1;
if ( !array_key_exists( $beyond, $array) )
$array[ $beyond ] = NULL;
$json = json_encode( $array, JSON_PRESERVE_ZERO_FRACTION+JSON_UNESCAPED_UNICODE );
?>
Of course, your later code has to treat an element with a "NULL" value the same as "!isset()", if it iterates the array.Warning about JSON_NUMERIC_CHECK and scientific notation.
JSON_NUMERIC_CHECK will remove scientific notation. Thus,
json_encode(['scientificNumber' => '1e-4'], JSON_NUMERIC_CHECK);
will return {"scientificNumber":0.0001}
You have to account for this, as it may defeat the whole purpose of scientific notation.flags JSON_NUMERIC_CHECK and JSON_PRESERVE_ZERO_FRACTION are broken in php 7+ — json_encode((float)8.8) returns "8.8000000000000007", and json_encode((float)8.8, JSON_NUMERIC_CHECK) and json_encode((float)8.8, JSON_PRESERVE_ZERO_FRACTION) return "8.8000000000000007" too.
the only way to fix this is setting "serialize_precision = -1" in php.ini