json-decode
json_decode
Decodes a JSON string
ENTITY
mixed
json_decode
string
json
bool
null
associative
ENTITY
int
depth
512
int
flags
0
Takes a JSON encoded string and converts it into a PHP value.
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json
The json string being decoded.
This function only works with UTF-8 encoded strings.
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associative
When ENTITY, JSON objects will be returned as associative ENTITYs; when ENTITY, JSON objects will be returned as ENTITYs. When ENTITY, JSON objects will be returned as associative ENTITYs or ENTITYs depending on whether JSON_OBJECT_AS_ARRAY is set in the flags.
depth
Maximum nesting depth of the structure being decoded. The value must be greater than 0, and less than or equal to 2147483647.
flags
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.
ENTITY
Returns the value encoded in json as an appropriate PHP type. Unquoted values true, false and null are returned as ENTITY, ENTITY and ENTITY respectively. ENTITY is returned if the json cannot be decoded or if the encoded data is deeper than the nesting limit.
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If depth is outside the allowed range, a ValueError is thrown as of PHP 8.0.0, while previously, an error of level E_WARNING was raised.
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| ENTITY | ENTITY |
|---|---|
| 7.3.0 | JSON_THROW_ON_ERROR flags was added. |
| 7.2.0 | associative is nullable now. |
| 7.2.0 | JSON_INVALID_UTF8_IGNORE, and JSON_INVALID_UTF8_SUBSTITUTE flags 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_. |
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json_decode examples
<?php
$json = '{"a":1,"b":2,"c":3,"d":4,"e":5}';
var_dump(json_decode($json));
var_dump(json_decode($json, true));
?>
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object(stdClass)#1 (5) {
["a"] => 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.
<?php
$json = '{"foo-bar": 12345}';
$obj = json_decode($json);
print $obj->{'foo-bar'}; // 12345
?>
common mistakes using json_decode
<?php
// the following strings are valid JavaScript but not valid JSON
// the name and value must be enclosed in double quotes
// single quotes are not valid
$bad_json = "{ 'bar': 'baz' }";
json_decode($bad_json); // null
// the name must be enclosed in double quotes
$bad_json = '{ bar: "baz" }';
json_decode($bad_json); // null
// trailing commas are not allowed
$bad_json = '{ bar: "baz", }';
json_decode($bad_json); // null
?>
depth errors
<?php
// Encode some data with a maximum depth of 4 (array -> array -> array -> string)
$json = json_encode(
array(
1 => array(
'English' => array(
'One',
'January'
),
'French' => array(
'Une',
'Janvier'
)
)
)
);
// Show the errors for different depths.
var_dump(json_decode($json, true, 4));
echo 'Last error: ', json_last_error_msg(), PHP_EOL, PHP_EOL;
var_dump(json_decode($json, true, 3));
echo 'Last error: ', json_last_error_msg(), PHP_EOL, PHP_EOL;
?>
ENTITY
array(1) {
[1]=>
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: No error
NULL
Last error: Maximum stack depth exceeded
json_decode of large integers
<?php
$json = '{"number": 12345678901234567890}';
var_dump(json_decode($json));
var_dump(json_decode($json, false, 512, JSON_BIGINT_AS_STRING));
?>
ENTITY
object(stdClass)#1 (1) {
["number"]=>
float(1.2345678901235E+19)
}
object(stdClass)#1 (1) {
["number"]=>
string(20) "12345678901234567890"
}
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[!NOTE] The JSON spec is not JavaScript, but a subset of JavaScript.
[!NOTE] In the event of a failure to decode,
json_last_errorcan be used to determine the exact nature of the error.
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json_encode, json_last_error, json_last_error_msg
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