json_decode

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

json_decodeDecodes a JSON string

Опис

mixed json_decode ( string $json [, bool $assoc = false [, int $depth = 512 [, int $options = 0 ]]] )

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

Параметри

json

The json string being decoded.

This function only works with UTF-8 encoded strings.

Зауваження:

PHP implements a superset of JSON as specified in the original » RFC 4627 - it will also encode and decode scalar types and NULL. RFC 4627 only supports these values when they are nested inside an array or an object.

Although this superset is consistent with the expanded definition of "JSON text" in the newer » RFC 7159 (which aims to supersede RFC 4627) and » ECMA-404, this may cause interoperability issues with older JSON parsers that adhere strictly to RFC 4627 when encoding a single scalar value.

assoc

When TRUE, returned objects will be converted into associative arrays.

depth

User specified recursion depth.

options

Bitmask of JSON decode options. Currently only JSON_BIGINT_AS_STRING is supported (default is to cast large integers as floats)

Значення, що повертаються

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.

Приклади

Приклад #1 json_decode() examples

<?php
$json 
'{"a":1,"b":2,"c":3,"d":4,"e":5}';

var_dump(json_decode($json));
var_dump(json_decode($jsontrue));

?>

Наведений 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 the data.
$json json_encode(
    array(
        
=> 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(43, -1) as $depth) {
    
var_dump(json_decode($jsontrue$depth));
    echo 
'Last error: '$json_errors[json_last_error()], PHP_EOLPHP_EOL;
}
?>

Наведений 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: JSON_ERROR_NONE

NULL
Last error: JSON_ERROR_DEPTH

Приклад #5 json_decode() of large integers

<?php
$json 
'{"number": 12345678901234567890}';

var_dump(json_decode($json));
var_dump(json_decode($jsonfalse512JSON_BIGINT_AS_STRING));

?>

Наведений 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.

Журнал Змін

Версія Опис
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.
5.4.0 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.

Прогляньте Також

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User Contributed Notes 4 notes

up
1
Alien426
1 year ago
Browsers don't choke on integers _starting_ with BigInt (64 bits), but before that (53 bits). The introduction of BigInt to modern browsers doesn't help much, when JSON handling functions do not support it. So I am trying to remedy that. My approach is to handle the decoded array before re-encoding it to a string:
<?php
function fix_large_int(&$value)
{
  if (
is_int($value) && $value > 9007199254740991)
   
$value = strval($value);
}
$json_str = '{"id":[1234567890123456789,12345678901234567890]}';
$json_arr = json_decode($json_str, flags: JSON_BIGINT_AS_STRING | JSON_OBJECT_AS_ARRAY);
echo(
json_encode($json_arr)); // {"id":[1234567890123456789,"12345678901234567890"]} (BigInt is already converted to a string here)
array_walk_recursive($json_arr, 'fix_large_int');
echo(
json_encode($json_arr)); // {"id":["1234567890123456789","12345678901234567890"]}
?>
up
0
greaties at ghvernuft dot nl
1 year ago
To load an object with data in json format:

function loadJSON($Obj, $json)
{
    $dcod = json_decode($json);
    $prop = get_object_vars ( $dcod );
    foreach($prop as $key => $lock)
    {
        if(property_exists ( $Obj ,  $key ))
        {
            if(is_object($dcod->$key))
            {
                loadJSON($Obj->$key, json_encode($dcod->$key));
            }
            else
            {
                $Obj->$key = $dcod->$key;
            }
        }
    }
}
up
0
cubefox at web dot NOSPAMPLEASE dot de
1 year ago
Warning: As the section "return values" mentions, the return value NULL is ambiguos. To repeat, it can mean three things:

* The input string had the value "null"
* There was an error while parsing the input data
* The encoded data was deeper than the recursion limit

To distinguish these cases, json_last_error() can be used.
up
-7
mattia
1 year ago
if you're using ajax to post, and your JavaScript code looks like this:

<code>
    var xhttp = new XMLHttpRequest();
    xhttp.open("POST", "something.php", true);
    xhttp.setRequestHeader("Content-Type", "application/json");
    xhttp.onreadystatechange = function() {
        if (this.readyState == 4 && this.status == 200) {
             // do something
        }
    };
    var data = {some: "thing"};
    xhttp.send(JSON.stringify(data));
</code>

then in <code>something.php</code> you can retrieve your json by doing

<?php
$data
= json_decode(file_get_contents("php://input"), true);
?>
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