(PHP 5 >= 5.2.0, PHP 7, PECL json >= 1.2.0)
json_decode — Decodes a JSON string
json_decode ( string $json [, bool|null $associative = null [, int $depth = 512 [, int $flags = 0 ]]] ) : mixed
Takes a JSON encoded string and converts it into a PHP variable.
json
The json string being decoded.
This function only works with UTF-8 encoded strings.
Note:
PHP implements a superset of JSON as specified in the original » RFC 7159.
associative
When true, JSON objects will be returned as associative arrays; when false, JSON objects will be returned as objects. When null, JSON objects will be returned as associative arrays or objects depending on whether JSON_OBJECT_AS_ARRAY is set in the flags.
depth
Maximum nesting depth of the structure being decoded.
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.
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 nesting limit.
| Version | Description |
|---|---|
| 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_. |
Example #1 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));
?> The above example will output:
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)
}
Example #2 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
?> Example #3 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
?> Example #4 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; ?>
The above example will output:
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
Example #5 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));
?> The above example will output:
object(stdClass)#1 (1) {
["number"]=>
float(1.2345678901235E+19)
}
object(stdClass)#1 (1) {
["number"]=>
string(20) "12345678901234567890"
}
Note:
The JSON spec is not JavaScript, but a subset of JavaScript.
Note:
In the event of a failure to decode, json_last_error() can be used to determine the exact nature of the error.
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Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.json-decode.php