json_decodeDecodes a JSON string
&reftitle.description;
mixedjson_decodestringjsonboolassoc&false;intdepth512intoptions0
Takes a JSON encoded string and converts it into a PHP variable.
&reftitle.parameters;
json
The jsonstring being decoded.
This function only works with UTF-8 encoded strings.
&json.implementation.superset;
assoc
When &true;, returned &object;s will be converted into
associative &array;s.
depth
User specified recursion depth.
options
Bitmask of
JSON_BIGINT_AS_STRING,
JSON_INVALID_UTF8_IGNORE,
JSON_INVALID_UTF8_SUBSTITUTE,
JSON_OBJECT_AS_ARRAY,
JSON_THROW_ON_ERROR.
The behaviour of these constants is described on the
JSON constants page.
&reftitle.returnvalues;
Returns the value encoded in json in appropriate
PHP type. Values true, false and
null are returned as &true;, &false; and &null;
respectively. &null; is returned if the json cannot
be decoded or if the encoded data is deeper than the recursion limit.
&reftitle.changelog;
&Version;&Description;7.3.0JSON_THROW_ON_ERRORoptions was added.
7.2.0JSON_INVALID_UTF8_IGNORE, and
JSON_INVALID_UTF8_SUBSTITUTEoptions were added.
7.1.0
An empty JSON key ("") can be encoded to the empty object property
instead of using a key with value _empty_.
7.0.0
Rejected RFC 7159 incompatible number formats - top level
(07, 0xff, .1, -.1) and all levels ([1.], [1.e1])
7.0.0
An empty PHP string or value that after casting to string is an empty
string (NULL, FALSE) results
in JSON syntax error.
5.6.0
Invalid non-lowercased variants of the true,
false and null literals are no
longer accepted as valid input, and will generate warnings.
5.4.0JSON_BIGINT_AS_STRING, and
JSON_OBJECT_AS_ARRAYoptions were added.
5.4.0
The options parameter was added.
5.3.0
Added the optional depth. The default
recursion depth was increased from 128 to 512
5.2.3
The nesting limit was increased from 20 to 128
5.2.1
Added support for JSON decoding of basic types.
&reftitle.examples;
<function>json_decode</function> examples
]]>
&example.outputs;
int(1)
["b"] => int(2)
["c"] => int(3)
["d"] => int(4)
["e"] => int(5)
}
array(5) {
["a"] => int(1)
["b"] => int(2)
["c"] => int(3)
["d"] => int(4)
["e"] => int(5)
}
]]>
Accessing invalid object properties
Accessing elements within an object that contain characters not
permitted under PHP's naming convention (e.g. the hyphen) can be
accomplished by encapsulating the element name within braces and the apostrophe.
{'foo-bar'}; // 12345
?>
]]>
common mistakes using <function>json_decode</function>
]]>
<parameter>depth</parameter> errors
array(
'English' => array(
'One',
'January'
),
'French' => array(
'Une',
'Janvier'
)
)
)
);
// Define the errors.
$constants = get_defined_constants(true);
$json_errors = array();
foreach ($constants["json"] as $name => $value) {
if (!strncmp($name, "JSON_ERROR_", 11)) {
$json_errors[$value] = $name;
}
}
// Show the errors for different depths.
foreach (range(4, 3, -1) as $depth) {
var_dump(json_decode($json, true, $depth));
echo 'Last error: ', $json_errors[json_last_error()], PHP_EOL, PHP_EOL;
}
?>
]]>
&example.outputs;
array(2) {
["English"]=>
array(2) {
[0]=>
string(3) "One"
[1]=>
string(7) "January"
}
["French"]=>
array(2) {
[0]=>
string(3) "Une"
[1]=>
string(7) "Janvier"
}
}
}
Last error: JSON_ERROR_NONE
NULL
Last error: JSON_ERROR_DEPTH
]]>
<function>json_decode</function> of large integers
]]>
&example.outputs;
float(1.2345678901235E+19)
}
object(stdClass)#1 (1) {
["number"]=>
string(20) "12345678901234567890"
}
]]>
&reftitle.notes;
The JSON spec is not JavaScript, but a subset of JavaScript.
In the event of a failure to decode, json_last_error
can be used to determine the exact nature of the error.
&reftitle.seealso;
json_encodejson_last_error