Funciones de JSON
I added a 3rd regex to the json_decode_nice function by "colin.mollenhour.com" to handle a trailing comma in json definition.
<?php
// http://www.php.net/manual/en/function.json-decode.php#95782
function json_decode_nice($json, $assoc = FALSE){
$json = str_replace(array("\n","\r"),"",$json);
$json = preg_replace('/([{,]+)(\s*)([^"]+?)\s*:/','$1"$3":',$json);
$json = preg_replace('/(,)\s*}$/','}',$json);
return json_decode($json,$assoc);
}
?>
Example:
<?php
$dat_json = <<<EOF
{
"foo" : "bam",
"bar" : "baz",
}
EOF;
$dat_array = json_decode_nice( $dat_json );
var_dump ( $dat_json, $dat_array );
/* RESULTS:
string(35) "{
"foo" : "bam",
"bar" : "baz",
}"
array(2) {
["foo"]=>
string(3) "bam"
["bar"]=>
string(3) "baz"
}
*/
?>
json_decode
(PHP 5 >= 5.2.0, PECL json >= 1.2.0)
json_decode — Decodifica un string JSON
Descripción
mixed json_decode
( string
$json
[, bool $assoc = false
[, int $depth = 512
[, int $options = 0
]]] )Convierte un string codificado en JSON en una variable PHP.
Parámetros
-
json -
El string
jsona ser decodificado.Esta función sólo funciona con datos codificados en UTF-8.
-
assoc -
Cuando es
TRUE, los objects retornados se convertirán en arrays asociativos. -
depth -
Máxima profudidad de recursión.
-
options -
Opciones de decodificación Bitmask de JSON. Actualmente solo
JSON_BIGINT_AS_STRINGestá soportado (por defecto castea enteros largos como flotantes)
Valores devueltos
Retorna el valor codificado de json en un tipo PHP
apropiado. Los valores true, false y
null (case-insensitive) se retornan como TRUE, FALSE
y NULL respectivamente. NULL se retorna si no se puede decodificar
json o si los datos superan el límite de profundidad
de recursión indicado por depth.
Ejemplos
Ejemplo #1 Ejemplos de json_decode()
<?php
$json = '{"a":1,"b":2,"c":3,"d":4,"e":5}';
var_dump(json_decode($json));
var_dump(json_decode($json, true));
?>
El resultado del ejemplo sería:
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)
}
Ejemplo #2 Accediendo a propiedades del objecto no válidas
Se puede acceder a elementos del objecto que contienen caracteres no permitidos bajo la convención de nombres de PHP (p.ej. el guión) encapsulando el nombre del elemento entre claves y comillas.
<?php
$json = '{"foo-bar": 12345}';
$obj = json_decode($json);
print $obj->{'foo-bar'}; // 12345
?>
Ejemplo #3 Errores comunes al usar json_decode()
<?php
// los siguientes strings son válidos en JavaScript pero no en JSON
// el nombre y el valor deben rodearse por dobles comillas
// las comillas simples no son válidas
$bad_json = "{ 'bar': 'baz' }";
json_decode($bad_json); // null
// el nombre debe roderarse por dobles comillas
$bad_json = '{ bar: "baz" }';
json_decode($bad_json); // null
// las comas finales no se permiten
$bad_json = '{ bar: "baz", }';
json_decode($bad_json); // null
?>
Ejemplo #4 Errores de depth
<?php
// Codificar los datos.
$json = json_encode(
array(
1 => array(
'Inglés' => array(
'One',
'January'
),
'Francés' => array(
'Une',
'Janvier'
)
)
)
);
// Definimos los errores.
$constants = get_defined_constants(true);
$json_errors = array();
foreach ($constants["json"] as $name => $value) {
if (!strncmp($name, "JSON_ERROR_", 11)) {
$json_errors[$value] = $name;
}
}
// Mostramos los errores para diferentes profundidades.
foreach (range(4, 3, -1) as $depth) {
var_dump(json_decode($json, true, $depth));
echo 'Último error: ', $json_errors[json_last_error()], PHP_EOL, PHP_EOL;
}
?>
El resultado del ejemplo sería:
array(1) {
[1]=>
array(2) {
["Inglés"]=>
array(2) {
[0]=>
string(3) "One"
[1]=>
string(7) "January"
}
["Francés"]=>
array(2) {
[0]=>
string(3) "Une"
[1]=>
string(7) "Janvier"
}
}
}
Último error: JSON_ERROR_NONE
NULL
Último error: JSON_ERROR_NONE
Ejemplo #5 json_decode() de enteros largos
<?php
$json = '{"number": 12345678901234567890}';
var_dump(json_decode($json));
var_dump(json_decode($json, false, 512, JSON_BIGINT_AS_STRING));
?>
El resultado del ejemplo sería:
object(stdClass)#1 (1) {
["number"]=>
float(1.2345678901235E+19)
}
object(stdClass)#1 (1) {
["number"]=>
string(20) "12345678901234567890"
}
Notas
Nota:
La espeficación JSON no es JavaScript, pero sí un subconjunto de JavaScript.
Nota:
En el caso de error al decodificar, json_last_error() se puede usar para determinar la naturaleza exacta del error.
Historial de cambios
| Versión | Descripción |
|---|---|
| 5.4.0 |
Se añadió el parámetro options.
|
| 5.3.0 | Añadido el parámetro opcional depth. La profundidad de recursión por defecto se incrementó de 128 a 512 |
| 5.2.3 | La profundidad de recursión por defecto se incrementó de 20 a 128 |
| 5.2.1 | Se añadió el soporte para la decodificación JSON de tipos básicos. |
Ver también
- json_encode() - Retorna la representación JSON representation del valor dado
- json_last_error() - Devuelve el último error que ocurrió
add a note
User Contributed Notes
json_decode - [17 notes]
phpdoc at badassawesome dot com ¶
2 months ago
1franck ¶
3 months ago
Sometime, i need to allow comments in json file. So i wrote a small func to clean comments in a json string before decoding it:
<?php
/**
* Clean comments of json content and decode it with json_decode().
* Work like the original php json_decode() function with the same params
*
* @param string $json The json string being decoded
* @param bool $assoc When TRUE, returned objects will be converted into associative arrays.
* @param integer $depth User specified recursion depth. (>=5.3)
* @param integer $options Bitmask of JSON decode options. (>=5.4)
* @return string
*/
function json_clean_decode($json, $assoc = false, $depth = 512, $options = 0) {
// search and remove comments like /* */ and //
$json = preg_replace("#(/\*([^*]|[\r\n]|(\*+([^*/]|[\r\n])))*\*+/)|([\s\t](//).*)#", '', $json);
if(version_compare(phpversion(), '5.4.0', '>=')) {
$json = json_decode($json, $assoc, $depth, $options);
}
elseif(version_compare(phpversion(), '5.3.0', '>=')) {
$json = json_decode($json, $assoc, $depth);
}
else {
$json = json_decode($json, $assoc);
}
return $json;
}
?>
jrevillini ¶
4 years ago
When decoding strings from the database, make sure the input was encoded with the correct charset when it was input to the database.
I was using a form to create records in the DB which had a content field that was valid JSON, but it included curly apostrophes. If the page with the form did not have
<meta http-equiv="Content-Type" content="text/html;charset=utf-8">
in the head, then the data was sent to the database with the wrong encoding. Then, when json_decode tried to convert the string to an object, it failed every time.
Aaron Kardell ¶
4 years ago
Make sure you pass in utf8 content, or json_decode may error out and just return a null value. For a particular web service I was using, I had to do the following:
<?php
$contents = file_get_contents($url);
$contents = utf8_encode($contents);
$results = json_decode($contents);
?>
Hope this helps!
T erkif ¶
2 years ago
it seems, that some of the people are not aware, that if you are using json_decode to decode a string it HAS to be a propper json string:
<?php
var_dump(json_encode('Hello'));
var_dump(json_decode('Hello')); // wrong
var_dump(json_decode("Hello")); // wrong
var_dump(json_decode('"Hello"')); // correct
var_dump(json_decode("'Hello'")); // wrong
result:
string(7) ""Hello""
NULL
NULL
string(5) "Hello"
NULL
Gravis ¶
4 years ago
with two lines you can convert your string from JavaScript toSource() (see http://www.w3schools.com/jsref/jsref_toSource.asp) output format to JSON accepted format. this works with subobjects too!
note: toSource() is part of JavaScript 1.3 but only implemented in Mozilla based javascript engines (not Opera/IE/Safari/Chrome).
<?php
$str = '({strvar:"string", number:40, boolvar:true, subobject:{substrvar:"sub string", subsubobj:{deep:"deeply nested"}, strnum:"56"}, false_val:false, false_str:"false"})'; // example javascript object toSource() output
$str = substr($str, 1, strlen($str) - 2); // remove outer ( and )
$str = preg_replace("/([a-zA-Z0-9_]+?):/" , "\"$1\":", $str); // fix variable names
$output = json_decode($str, true);
var_dump($output);
?>
var_dump output:
array(6) {
["strvar"]=>
string(6) "string"
["number"]=>
int(40)
["boolvar"]=>
bool(true)
["subobject"]=>
array(3) {
["substrvar"]=>
string(10) "sub string"
["subsubobj"]=>
array(1) {
["deep"]=>
string(13) "deeply nested"
}
["strnum"]=>
string(2) "56"
}
["false_val"]=>
bool(false)
["false_str"]=>
string(5) "false"
}
hope this saves someone some time.
php at hm2k.org ¶
3 years ago
If var_dump produces NULL, you may be experiencing JSONP aka JSON with padding, here's a quick fix...
<?php
//remove padding
$body=preg_replace('/.+?({.+}).+/','$1',$body);
// now, process the JSON string
$result = json_decode($body);
var_dump($result);
?>
skypppher at gmail dot com ¶
6 months ago
First of all, since JSON is not native PHP format or even native JavaScript format, everyone who wants to use JSON wisely should carefuly read official documentation. There is a link to it here, in "Introduction" section. Many questions like "it doesn't recognize my strings" and those like previous one (about zip codes) will drop if you will be attentive!
And second. I've found that there is no good, real working example of how to validate string if it is a JSON or not.
There are two ways to make this: parse input string for yourself using regular expressions or anything else, use json_decode to do it for you.
Parsing for yourself is like writing your own compiler, too difficult.
Just testing result of json_decode is not enough because you should test it with NULL, but valid JSON could be like this 'null' and it will evaluate to NULL. So you should use another function - json_last_error. It will return error code of the last encode/decode operation. If no error occured it will be JSON_ERROR_NONE. So here is the function you should use for testing:
<?php
function isValidJson($strJson) {
json_decode($strJson);
return (json_last_error() === JSON_ERROR_NONE);
}
?>
It's so simple, that there is no need to use it and slow down your script with extra delay for function call. Just do it manualy in you code while working with input data:
<?php
//here is my initial string
$sJson = $_POST['json'];
//try to decode it
$json = json_decode($sJson);
if (json_last_error() === JSON_ERROR_NONE) {
//do something with $json. It's ready to use
} else {
//yep, it's not JSON. Log error or alert someone or do nothing
}
?>
php_net_01_weber at nachvorne de ¶
1 month ago
json_decode_nice + keep linebreaks:
function json_decode_nice($json, $assoc = TRUE){
$json = str_replace(array("\n","\r"),"\\n",$json);
$json = preg_replace('/([{,]+)(\s*)([^"]+?)\s*:/','$1"$3":',$json);
$json = preg_replace('/(,)\s*}$/','}',$json);
return json_decode($json,$assoc);
}
by phpdoc at badassawesome dot com, I just changed line 2.
If you want to keep the linebreaks just escape the slash.
premiersullivan at gmail dot com ¶
3 years ago
This function will remove trailing commas and encode in utf8, which might solve many people's problems. Someone might want to expand it to also change single quotes to double quotes, and fix other kinds of json breakage.
<?php
function mjson_decode($json)
{
return json_decode(removeTrailingCommas(utf8_encode($json)));
}
function removeTrailingCommas($json)
{
$json=preg_replace('/,\s*([\]}])/m', '$1', $json);
return $json;
}
?>
colin.mollenhour.com ¶
3 years ago
For those of you wanting json_decode to be a little more lenient (more like Javascript), here is a wrapper:
<?php
function json_decode_nice($json, $assoc = FALSE){
$json = str_replace(array("\n","\r"),"",$json);
$json = preg_replace('/([{,]+)(\s*)([^"]+?)\s*:/','$1"$3":',$json);
return json_decode($json,$assoc);
}
?>
Some examples of accepted syntax:
<?php
$json = '{a:{b:"c",d:["e","f",0]}}';
$json =
'{
a : {
b : "c",
"d.e.f": "g"
}
}';
?>
If your content needs to have newlines, do this:
<?php
$string = "This
Text
Has
Newlines";
$json = '{withnewlines:'.json_encode($string).'}';
?>
Note: This does not fix trailing commas or single quotes.
[EDIT BY danbrown AT php DOT net: Contains a bugfix provided by (sskaje AT gmail DOT com) on 05-DEC-2012 with the following note.]
Old regexp failed when json like
{aaa:[{a:1},{a:2}]}
majca J ¶
3 years ago
Noted in a comment below is that this function will return NULL when given a simple string.
This is new behavior - see the result in PHP 5.2.4 :
php > var_dump(json_decode('this is a simple string'));
string(23) "this is a simple string"
in PHP 5.3.2 :
php > var_dump(json_decode('this is a simple string'));
NULL
I had several functions that relied on checking the value of a purported JSON string if it didn't decode into an object/array. If you do too, be sure to be aware of this when upgrading to PHP 5.3.
alexvonweiss at googlemail dot com ¶
1 year ago
Consider that JSON can differ between int and string. So
<?php
var_dump(json_decode('{"foo": 12}'));
// array(1) { ["foo"]=> int(12) }
var_dump(json_decode('{"foo": "12"}'));
// array(1) { ["foo"]=> string(12) }
?>
Numbers that cannot be handled by integer seems to become float casted. This can be a problem if you transfer big numbers like facebook ids over JSON. Either you avoid numbers by cast everything to string before JSON.stringify or you have to use number_format if the value bacome a float value.
<?php
// test
$x = json_decode('{"foo": 123456789012345}');
echo sprintf('%1$f', $x->foo).PHP_EOL;
echo sprintf('%1$u', $x->foo).PHP_EOL;
echo sprintf('%1$s', $x->foo).PHP_EOL;
echo strval($x->foo).PHP_EOL;
echo (string) $x->foo.PHP_EOL;
echo number_format($x->foo, 0, '', '').PHP_EOL;
// output
123456789012345.000000 // printf %f
2249056121 // printf %u
1.2345678901234E+14 // printf %s
1.2345678901234E+14 // strval()
1.2345678901234E+14 // cast (string)
2249056121 // cast (int)
123456789012345 // number_format()
?>
steven at acko dot net ¶
4 years ago
json_decode()'s handling of invalid JSON is very flaky, and it is very hard to reliably determine if the decoding succeeded or not. Observe the following examples, none of which contain valid JSON:
The following each returns NULL, as you might expect:
<?php
var_dump(json_decode('[')); // unmatched bracket
var_dump(json_decode('{')); // unmatched brace
var_dump(json_decode('{}}')); // unmatched brace
var_dump(json_decode('{error error}')); // invalid object key/value
notation
var_dump(json_decode('["\"]')); // unclosed string
var_dump(json_decode('[" \x "]')); // invalid escape code
Yet the following each returns the literal string you passed to it:
var_dump(json_decode(' [')); // unmatched bracket
var_dump(json_decode(' {')); // unmatched brace
var_dump(json_decode(' {}}')); // unmatched brace
var_dump(json_decode(' {error error}')); // invalid object key/value notation
var_dump(json_decode('"\"')); // unclosed string
var_dump(json_decode('" \x "')); // invalid escape code
?>
(this is on PHP 5.2.6)
Reported as a bug, but oddly enough, it was closed as not a bug.
[NOTE BY danbrown AT php DOT net: This was later re-evaluated and it was determined that an issue did in fact exist, and was patched by members of the Development Team. See http://bugs.php.net/bug.php?id=45989 for details.]
evengard at trioptimum dot com ¶
2 years ago
There is a problem when passing to json_decode a string with the "\" symbol. It seems to identify it as an escape character and trying to follow it. So sometimes it leads to failed parsing.
It seems that just replacing it with "\\" helps.
<?php
print_r(json_decode(str_replace('\\', '\\\\', '{"name":"/\"}')));
?>
where /\ is the string which doesn't worked.
nospam (AT) hjcms (DOT) de ¶
6 years ago
You can't transport Objects or serialize Classes, json_* replace it bei stdClass!
<?php
$dom = new DomDocument( '1.0', 'utf-8' );
$body = $dom->appendChild( $dom->createElement( "body" ) );
$body->appendChild( $dom->createElement( "forward", "Hallo" ) );
$JSON_STRING = json_encode(
array(
"aArray" => range( "a", "z" ),
"bArray" => range( 1, 50 ),
"cArray" => range( 1, 50, 5 ),
"String" => "Value",
"stdClass" => $dom,
"XML" => $dom->saveXML()
)
);
unset( $dom );
$Search = "XML";
$MyStdClass = json_decode( $JSON_STRING );
// var_dump( "<pre>" , $MyStdClass , "</pre>" );
try {
throw new Exception( "$Search isn't a Instance of 'stdClass' Class by json_decode()." );
if ( $MyStdClass->$Search instanceof $MyStdClass )
var_dump( "<pre>instanceof:" , $MyStdClass->$Search , "</pre>" );
} catch( Exception $ErrorHandle ) {
echo $ErrorHandle->getMessage();
if ( property_exists( $MyStdClass, $Search ) ) {
$dom = new DomDocument( "1.0", "utf-8" );
$dom->loadXML( $MyStdClass->$Search );
$body = $dom->getElementsByTagName( "body" )->item(0);
$body->appendChild( $dom->createElement( "rewind", "Nice" ) );
var_dump( htmlentities( $dom->saveXML(), ENT_QUOTES, 'utf-8' ) );
}
}
?>
nix ¶
3 years ago
Be aware, when decoding JSON strings, where an empty string is a key, this library replaces the empty string with "_empty_".
So the following code gives an unexpected result:
<?php
var_dump(json_decode('{"":"arbitrary"}'));
?>
The result is as follows:
object(stdClass)#1 (1) {
["_empty_"]=>
string(6) "arbitrary"
}
Any subsequent key named "_empty_" (or "" [the empty string] again) will overwrite the value.