json_decode syntax error from valid json [closed] - php

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I have this simple JSON string :
{"type_voie":"ALL","indice_repetition":"B","num_voie":"1","nom_voie":"Azrty","infos_voie":"Zzz","distribution_speciale":"","cp":"34230","ville":"PLAISSAN","bureau_distributeur":""}
That I get from my utf8 database.
When I pass it to json_decode($json, true), the result is NULL and json_last_error() give me 4 (JSON_ERROR_SYNTAX)
If I do mb_detect_encoding, I can see that the string is in ASCII, but I only use UTF-8 everywhere.
The string was originally inserted in database from an AJAX query. I got the date from a form serialized with the jQuery function serialize().
I did this a lot in my project and never had problem like this.
I tried to force UTF8 using iconv, mb_convert_encoding or ut8_encode, but nothing change.
I also tried with html_entity_decode() because sometimes PDO is replacing the quotes, but same result.
EDIT :
OH MY GOD.
SORRY.
For some reasons, a was concatenated between the moment I get the json and the moment I send it to the parser.
There was just PEBKAC....
I'm so ashamed.
Will delete this post soon

Answer 1

As we found in the comments that there are invisible characters in the string, consider running this bit of code. It should show you each character in the string, it'd ascii value and it's printed version.
There should be a few characters in there which do not print anything; those are the ones preventing you from json_encoding the string. I cannot see why they are in the string, that has something to do with your database and the data you post into it, but at least you'll know where the problem is.
Odds are they are contained inside the inserted data somewhere, which means you probably have a piece of code somewhere that add something unprintable to their input.
You can strip them while exporting, but it would be better to find out which code adds them and remove them from the database. They will continue to bother you in the future otherwise. (As you've seen at this point even something simple like strlen() will fail to work properly due to these characters)
for( $i = 0 ; $i < mb_strlen($string) ; $i++ ) {
echo 'pos: ' . $i . ' | ord: ' . ord( $string[$i] ) . ' | char: ' . $string[$i] . '<br />';
}

Answer 2

As guys pointed in previous answers, there can be unprintable characters in json, which means they should be removed before calling json_decode.
One way to do that is this:
$json = preg_replace('/[[:^print:]]/', '', $json);
I am not saying this is the best solution, but so far the only one I found that worked for me.

Answer 3

You have to encode your source with UTF-8 before using json_decode()
try with this code :
$json = mb_convert_encoding($json, "UTF-8");
var_dump(json_decode($json, true));

Answer 4

PHP CURL to API with JSON response
Syntax error, malformed JSON
json_last_error() === 4
JSON_ERROR_SYNTAX
In my situation, I was using PHP CURL to get JSON data from a local API.
I accidentally included HTML in the API's JSON response which caused the error.
After removing the inserted HTML from the API response page, json_decode() executed properly.
Why did this error occur?
CURL requests return the entire page content's as a string. This becomes problematic for json_decode() if content other than JSON is included in the string.
When print/echo'ing a CURL's JSON string on a web page, the string's content can be hidden within the HTML document.
Tip: use var_dump() to compare string lengths to determine if extra content has been included in the JSON string or inspect the page source code to determine if additional code has been included.

Answer 5

your valid json may be like this add [] in your array then generate json
[{"type_voie":"ALL","indice_repetition":"B","num_voie":"1","nom_voie":"Azrty","infos_voie":"Zzz","distribution_speciale":"","cp":"34230","ville":"PLAISSAN","bureau_distributeur":""}]