String appears to be valid JSON, but `json_decode()` returns NULL

Question

I think I\'ve found where the error lies:

    $convertJSON = file_get_contents(\"http://www.google.com/ig/calculator?hl=en&q=\" . $currencyValue . $curre         


        

Answer 1

Not a direct response to this question, but an issue I spent a few hours trying to resolve.

If you are attempting to decode JSON that came from a remote file via CURL, and if that file is in UTF-8 format, the beginning of the file may have the following characters (which breaks json_decode():



Which you will not see with the naked eye, only via htmlentities(); I have no idea why they are there, I traced this all the way to curl_exec(), thinking that maybe they were being added there. In any case, those little bastards were being added only when file is in UTF-8 format.

So, assuming you have no control over the encoding of the source file, you can do something like this before passing the string into json_decode():

$encoding = mb_detect_encoding($json);

if($encoding == 'UTF-8') {
  $json = preg_replace('/[^(\x20-\x7F)]*/','', $json);    
}    

print_r(json_decode($json));

I hope I save somebody some time, it took me a few hours of tracing to figure out that's what was happening.

Answer 2

to make json_encode workable, you have to add double quote to the result string in order to make it in JSON format.

I tries the simple code below , and it works fine:

$data = '{lhs: "1 U.S. dollar",rhs: "7.80177256 Hong Kong dollars",error: "",icc: true}';
$data = str_replace('lhs','"lhs"',$data);
$data = str_replace('rhs','"rhs"',$data);
$data = str_replace('error','"error"',$data);
$data = str_replace('icc','"icc"',$data);
print_r(json_decode($data));

Result:

stdClass Object ( [lhs] => 1 U.S. dollar [rhs] => 7.80177256 Hong Kong dollars [error] => [icc] => 1 ) 

Now it is in json_decode object!

Answer 3

Expanding on Matthews answer:

In case for some reason you want all data; (probably not but just in case?)

$c='{lhs: "1 British pound",rhs: "1.5358 U.S. dollars",error: "",icc: true}';
$j=json_decode(preg_replace('/({|,)([a-z]+): /','$1"$2": ',$c));
var_dump($j->{'rhs'});

I stumbled across this page before I worked it out so maybe others will too :)

Answer 4

The response Google is giving you isn't valid JSON because the labels are not quoted. You'll have to parse it yourself.

$response = '{lhs: "555 Euros",rhs: "796.64700 U.S. dollars",error: "",icc: true';
preg_match('/rhs:\s*"([^"]+)"/', $response, $m);
echo $m[1];

Output:

796.64700 U.S. dollars

Answer 5

strip it of everything but decimal points, commas, and numbers, and give me a result.

Actually you do the exact contrary with your regex. Add a ^ after [: [^ to negate it

$currencyValue = preg_replace('/([^0-9\.,]+)/', '', $currencyValue);