json_decode

(PHP 5 >= 5.2.0, PHP 7, PHP 8, PECL json >= 1.2.0)

json_decodeDecodes a JSON string

Опис

json_decode(
    string $json,
    ?bool $associative = null,
    int $depth = 512,
    int $flags = 0
): mixed

Takes a JSON encoded string and converts it into a PHP value.

Параметри

json

The json string being decoded.

This function only works with UTF-8 encoded strings.

Зауваження:

PHP реалізує повний набір JSON, як визначено в стандарті » 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. 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.

Значення, що повертаються

Returns the value encoded in json as an appropriate PHP type. Unquoted 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.

Помилки/виключення

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.

Журнал змін

Версія Опис
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_.

Приклади

Приклад #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));

?>

Поданий вище приклад виведе:

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)
}

Приклад #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

?>

Приклад #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

?>

Приклад #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;
?>

Поданий вище приклад виведе:

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

Приклад #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));

?>

Поданий вище приклад виведе:

object(stdClass)#1 (1) {
  ["number"]=>
  float(1.2345678901235E+19)
}
object(stdClass)#1 (1) {
  ["number"]=>
  string(20) "12345678901234567890"
}

Примітки

Зауваження:

The JSON spec is not JavaScript, but a subset of JavaScript.

Зауваження:

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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