json_decode返回空白

Question

I am working on facebook app. I have stored some values in database in json format.

When I am fetching the value on the target page and trying to display the value as follow :

$sql = mysql_query("select * from `beforepublish` where `tabid` = '$page_id'") or die(mysql_error());
$sql = mysql_fetch_assoc($sql);

$contest_id = $sql['contestid'];
$temp_id = $sql["tempid"];
$value = $sql["values"];
$returnValue = json_decode($value);
echo "<pre>";
print_r($returnValue);
echo "</pre>";

Here the value of

$value = {"image":"upload_1182341221.jpg","conttxt":"Get a chance to win Samsung Galaxy Tab "}

and I am getting $returnValue as blank.

but When I try :

$returnValue = json_decode('{"image":"upload_1182341221.jpg","conttxt":"Get a chance to win Samsung Galaxy Tab "}');
echo "<pre>";
print_r($returnValue);
echo "</pre>";

then $returnValue is returning :

stdClass Object
(
    [image] => upload_1182341221.jpg
    [conttxt] => Get a chance to win Samsung Galaxy Tab 
)

So guys, please help me, Why I am getting a blank value in the previous case ?

Edit

vardump($value) is returning :

string '{"image":"upload_1182341221.jpg","conttxt":"Get a chance to win Samsung Galaxy Tab
    "}' (length=86)

Answer 1

string '{"image":"upload_1182341221.jpg","conttxt":"Get a chance to win Samsung Galaxy Tab
    "}' (length=86)

There is your problem. That linebreak and tab. It should look like:

string '{"image":"upload_1182341221.jpg","conttxt":"Get a chance to win Samsung Galaxy Tab"}' (length=84)

This is why var_dump() outputs the length, so you can validate against any unwanted/invisible characters.

---

You can store line breaks in javascript strings as .
json_encode() will do this automatically.

This applies for all escape sequences (commonly used ones are , , \t and \b).