35

This does not work:

$jsonDecode = json_decode($jsonData, TRUE);

However if I copy the string from $jsonData and put it inside the decode function manually it does work.

This works:

$jsonDecode = json_decode('{"id":"0","bid":"918","url":"http:\/\/www.google.com","md5":"6361fbfbee69f444c394f3d2fa062f79","time":"2014-06-02 14:20:21"}', TRUE);

I did output $jsonData copied it and put in like above in the decode function. Then it worked. However if I put $jsonData directly in the decode function it does not.

var_dump($jsonData) shows:

string(144) "{"id":"0","bid":"918","url":"http:\/\/www.google.com","md5":"6361fbfbee69f444c394f3d2fa062f79","time":"2014-06-02 14:20:21"}"

But if count these character, there are only 124.

The $jsonData comes from a encrypted $_GET variable. To encrypt it I use this:

$key = "SOME KEY";

$iv_size = mcrypt_get_iv_size(MCRYPT_BLOWFISH, MCRYPT_MODE_ECB);
$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);

$enc = mcrypt_encrypt(MCRYPT_BLOWFISH, $key, $data, MCRYPT_MODE_ECB, $iv);

$iv = rawurlencode(base64_encode($iv));
$enc = rawurlencode(base64_encode($enc));

//To Decrypt
$iv = base64_decode(rawurldecode($_GET['i']));
$enc = base64_decode(rawurldecode($_GET['e']));

$data = mcrypt_decrypt(MCRYPT_BLOWFISH, $key, $enc, MCRYPT_MODE_ECB, $iv);
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5
  • 4
    In what way doesn't it work? What does it return? Do you have error reporting enabled, and are there any errors? Commented Jun 2, 2014 at 19:01
  • where does the jsonData come from? Commented Jun 2, 2014 at 19:04
  • 2
    There must be some invisible characters in your data because var_dump indicates there are 144 characters but your string only has 124 visible characters. Can you post the raw data somewhere or check it in an hex editor? Commented Jun 2, 2014 at 19:12
  • @Rob $jsonData comes from a encrypted $_GET variable. Commented Jun 2, 2014 at 19:13
  • 1
    When it fails, what does json_last_error return? us3.php.net/manual/en/function.json-last-error.php Commented Jun 2, 2014 at 19:19

18 Answers 18

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86

some time there is issue of html entities, for example \" it will represent like this \&quot, so you must need to parse the html entites to real text, that you can do using html_entity_decode() method of php. 

$jsonData = stripslashes(html_entity_decode($jsonData));

$k=json_decode($jsonData,true);

print_r($k);
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1 Comment

I don't see how this might resolve the asker's problem with invisible characters.
21

You have to use preg_replace for avoiding the null results from json_decode

here is the example code

$json_string = stripslashes(html_entity_decode($json_string));

$bookingdata =  json_decode( preg_replace('/[\x00-\x1F\x80-\xFF]/', '', $json_string), true );
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1 Comment

you save my day. thx a lot
14

Most likely you need to strip off the padding from your decrypted data. There are 124 visible characters in your string but var_dump reports 144. Which means 20 characters of padding needs to be removed (a series of "\0" bytes at the end of your string).

Probably that's 4 "\0" bytes at the end of a block + an empty 16-bytes block (to mark the end of the data).

How are you currently decrypting/encrypting your string?

Edit:

You need to add this to trim the zero bytes at the end of the string:

$jsonData = rtrim($jsonData, "\0");
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5 Comments

That's probably it. I edited my question and added how I encrypt the the $jsonData. However I don't see anything wrong with the encryption.
Could you also add how you decrypt the data? Encryption is fine but decryption seems to be where the problem is.
@user3630453, I've edited my answer. Adding the rtrim statement should fix the issue.
Many thanks! I know this might be unrelated to the question, but is this encryption ok? Or should I do it somehow else?
@user3630453, ECB is not very secure (prefer CBC) because the same data is encrypted to the same ciphertext. For the cipher you might want to choose a variant of AES-256, such as MCRYPT_RIJNDAEL_256. There's an example here, which should work fine - stackoverflow.com/a/3422787/561309
8

Judging from the other comments, you could use,

$jsonDecode = json_decode(trim($jsonData), TRUE);
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6

While moving on php 7.1 I encountered with json_decode error number 4 (json syntex error). None of the above solution on this page worked for me.

After doing some more searching i found solution at https://stackoverflow.com/a/15423899/1545384 and its working for me.

//Remove UTF8 Bom

function remove_utf8_bom($text)
{
    $bom = pack('H*','EFBBBF');
    $text = preg_replace("/^$bom/", '', $text);
    return $text;
}
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2

Interestingly mcrypt_decrypt seem to add control characters other than \0 at the end of the resulting text because of its padding algorithm. Therefore instead of rtrim($jsonData, "\0") it is recommended to use 

preg_replace( "/\p{Cc}*$/u", "", $data)

on the result $data of mcrypt_decrypt. json_decode will work if all trailing control characters are removed. Pl refer to the comment by Peter Bailey at http://php.net/manual/en/function.mdecrypt-generic.php .

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2

Be sure to set header to JSON

header('Content-type: application/json;');
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1 Comment

I don't see how this might resolve the asker's problem with invisible characters.
1

str_replace("\t", " ", str_replace("\n", " ", $string))

because json_decode does not work with special characters. And no error will be displayed. Make sure you remove tab spaces and new lines. Depending on the source you get your data, you might need also: stripslashes(html_entity_decode($string))

Works for me:

<?php

$sql = <<<EOT

    SELECT *
        FROM `students`;

EOT;
    $string = '{ "query" : "' . str_replace("\t", " ", str_replace("\n", " ", $sql)).'" }';
    print_r(json_decode($string));

?>

output:

stdClass Object
(
    [query] =>          SELECT *      FROM `students`;     
)
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1 Comment

I don't see how this might resolve the asker's problem with invisible characters. There is no indication of tabs or newlines being a problem.
1

I had problem that json_decode did not work, solution was to change string encoding to utf-8. This is important in case you have non-latin characters.

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1 Comment

I don't see how this might resolve the asker's problem with invisible characters.
0

USE THIS CODE

<?php 
   $json = preg_replace('/[[:cntrl:]]/', '', $json_data);
   $json_array = json_decode($json, true);
   echo json_last_error();
   echo json_last_error_msg();
   print_r($json_array);
?>
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Comments

0

Make sure your JSON is actually valid. For some reason I was convinced that this was valid JSON:

{ type: "block" }

While it is not. Point being, make sure to validate your string with a linter if you find json_decode not te be working.

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Comments

0

Try the JSON validator.

The problem in my case was it used ' not ", so I had to replace it to make it working.

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1 Comment

I don't see how this might resolve the asker's problem with invisible characters. Giving advice on how to get diagnostic details can be written as a comment under the question.
0

In notepad+ I changed encoding of json file on: "UTF-8 without BOM". JSON started to work

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Comments

-1

Maybe it helps someone, check in your json string if you have any NULL values, json_decode will not work if a NULL is present as a value.

This super basic function may help you. I made the NULL in an array just in case I need to add more stuff in the future.

function jsonValueFix($json){
    $json = str_replace( array('NULL'),'""',$json );
    return $json;
}
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1 Comment

Are you sure? I recommend you to check that again. And then to stop maiming your data with this awful destructive function
-1

TL;DR Be sure that your JSON not containing comments :)

I've taken a JSON structure from API reference and tested request using Postman. I've just copy-pasted the JSON and didn't pay attention that there was a comment inside it:

...
"payMethod": {
    "type": "PBL" //or "CARD_TOKEN", "INSTALLMENTS"
},
...

Of course after deletion the comment json_decode() started working like a charm :)

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1 Comment

I don't see how this might resolve the asker's problem with invisible characters.
-1

I had an error when I sent from ajax sent JSON.stringify(localStorage.getItem('orderFormData')). json_decode worked as soon as I removed JSON.stringify and started sending just a string

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2 Comments

This is more as comment or suggestion, not an answer perse, so I recommended you use the comment option instead.
I don't see how this might resolve the asker's problem with invisible characters.
-1

Assuming $jsonString contains your JSON data with potential hidden characters. You can use following code to remove such characters before decoding.

$jsonString = '...'; // Your JSON data

// Removing BOM and trimming whitespace
$jsonString = preg_replace('/\xEF\xBB\xBF|\xFE\xFF|\xFF\xFE|\x00/', '', trim($jsonString));

// Decode the JSON
$result = json_decode($jsonString);

if ($result === null && json_last_error() !== JSON_ERROR_NONE) {
    echo 'JSON decode error: ' . json_last_error_msg();
} else {
    // Use $result after successful decoding
    var_dump($result);
}
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Comments

-2

I just used json_decode twice and it worked for me

$response = json_decode($apiResponse, true);
$response = json_decode($response, true);
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1 Comment

I don't see how this might resolve the asker's problem with invisible characters.

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