The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.
The following constants indicate the type of error returned by json_last_error() or stored as the code of a 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 option was
given, null will be encoded in the place of the recursive reference.
JSON_ERROR_INF_OR_NAN
(int )
NAN
or INF .
If the JSON_PARTIAL_OUTPUT_ON_ERROR option was
given, 0 will be encoded in the place of these
special numbers.
JSON_ERROR_UNSUPPORTED_TYPE
(int )
JSON_PARTIAL_OUTPUT_ON_ERROR option was
given, null will be encoded in the place of the unsupported value.
JSON_ERROR_INVALID_PROPERTY_NAME
(int )
JSON_ERROR_UTF16
(int )
JSON_ERROR_NON_BACKED_ENUM
(int )
The following constants can be combined to form options for json_decode() .
JSON_BIGINT_AS_STRING
(int )
JSON_OBJECT_AS_ARRAY
(int )
true .
The following constants can be combined to form options for 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 is supplied. It uses the same
behaviour as it was before PHP 7.1 without this constant.
Available as of PHP 7.1.0.
The following constants can be combined to form options for json_decode() and json_encode() .
JSON_INVALID_UTF8_IGNORE
(int )
JSON_INVALID_UTF8_SUBSTITUTE
(int )
JSON_THROW_ON_ERROR
(int )
JSON_PARTIAL_OUTPUT_ON_ERROR takes precedence over
JSON_THROW_ON_ERROR .
Available as of PHP 7.3.0.
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